Sounds a lot like my backyard. My garden is highest in the middle, consistently slopes downward, has a somewhat steeper slope (dropping a good 3 feet in a couple feet) about two thirds of the way to the property line, is lower on both sides, but quite a lot lower on one side than the other. I put taller shrubs on the low side, shorter ones on the high side. BUT, I also had much different drainage conditions from one side to the other. If this is true for your friend's situation, then I believe the height of the shrubs is probably only a minor consideration. In my garden the high side has much better drainage, the low side holds water & sometimes lies in water. Plantings had to be quite different from side to side. Both sides are in full sun. For example, the center of the yard and part of the left lower side will grow a pine, the low areas on the right will kill a pine in one season. Finding deciduous plants & shrubs to suit both sides was fairly easy, finding evergreens in my climate was not. Since I didn't want to lose a lot of money experimenting with expensive shrubs and trees for the "wet garden" and a lot of the water loving ones get much too large for my smallish space and I'm a plantaholic anyway, the very low right side has more perennials than the left side, where I have a few shrub roses among the pines, daylilies, and grasses. (BTW, Itea & Clethra will grow on both sides). The perennials on the lowest side, such as water loving iris, are interspersed with a lot of cheap thicketing shrubs, like red twigs, and only a few tall arborvitaes (up the slope somewhat, where it is not too wet) for winter color and to balance the small rounded pines on the other side. Thus the height was more a function of what would grow well where. I mostly used color to unify the area, using a Blue Montgomery Spruce, 3 Crimson Pigmy Barberries, a Purple Leaf Sand Cherry & Purple Smokebush on one side & another Blue Montgomery Spruce, 3 more CP Barberries & 2 Physocarpus Diablo (which tolerate wet clay quite well) on the other side (toward the higher middle for drainage reasons) with a lot of red blooming perennials (quite different ones) on each side. I also used some tall grasses in place of shrubs in both areas, dry & wet and even planted bulbs on both sides, daffodils on the higher side and camassia on the other. Despite the fact that the spaces were different in size, I used a very similar bed shape on each side, trying for some additional symmetry that way, since the plantings were so different. Hope this gives you some ideas of the issues you can have with slopes and dropoffs.

It depends on what you will have in your drawers. My advice is to have your 36" base as 3-drawer and the two 24" bases as 4-drawer. Depending on where they are in relation to each other, the 24" could be one 3-drawer and one 4-drawer. We have frameless cabinets. I find we use Our top shallow drawers a LOT - they have 4" high useable space with a 6.25" drawer face. We have them all full of stuff ... silverware, spatulas and all the other kitchen gadgets, foil wax paper cling wrap and plastic baggies, in-drawer knife block and potholders, dish towels, etc. All of those things fit with no problem in these drawers including the ladle. In our two 3-drawer stacks (30" and 21" wide) the top drawer is the 4" drawer mentioned above, and the next two drawers have 10.5" and 9.5" high useable space, both with 12" drawer faces. Interestingly, the middle drawer is the 10.5" deep drawer. The 10.5" drawers are tall enough for all of the casserole dishes and pie tins (in 21"wide), the roasting pan, and almost all of the pans pots and lids to stand on edge (in 30"wide). The 9.5" drawers are not tall enough for a few of those items to stand on edge. Obviously, neither are tall enough for my 12" pans/skillets to stand on edge. Those are in the bottom 30" drawer with the big pots. Both depth drawers are definitely deep enough for all of the pots (even the 8qt stockpot) that I own except the huge "canning" pot. The bottom drawer of the 21" base is currently empty. In the two 4-drawer stacks (36" and 17" wide) the top drawer is the 4" drawer mentioned above, and the 2nd 3rd and 4th drawers are 4.75" 6.75" and 7" high useable interior space. The top 2 drawers have 6.25" drawer face and the bottom 2 drawers have 8.75" drawer face. The 2nd drawers at 4.75" we use for more kitchen gadgets and a junk drawer. The 3rd drawers at 6.75" holds all of our tupperware (any deeper would have been wasted space for us) and another junk drawer. The bottom drawers are currently empty except for plastic grocery store bags. I would definitely not recommend having 3 equal size drawers which would give you 3 drawers with approximately 8" high useable space ... way too tall for gadgets and stuff, but not tall enough for things on edge.

My dish drawer is across the aisle from my diswasher but I think the set up you are considering would be fine except for those times when someone is standing at the sink while you want unload the dishwasher. It wouldn't be a problem for me because I always unload my dshwasher first thing in the morning before anyone is up. You stated that you will have 2 six inch deep drawers and 2 that are nine inches deep. Is that the inside measurement of the drawers? Are your cabinets framed or frameless. If they are framed and that is the measurement of the front of the drawer box, the inside usable height will be less. My framed cabinetry drawers that are 10-3/4 inches on the front have an actual inside depth of only 7-5/8". If you haven't already done so you should measure the height of a stack of dishes you plan to store in the drawer (usually bowls will be the tallest stack), to make sure they will fit in your nine inch drawers. I love having my dishes in a drawer. Here is a picture of my 36" wide drawer filled with 8 place settings of my dishes. Oh and by the way, the peg system isn't really needed. I found that out after the fact.

Seems to me the objections to having two pulls on kitchen cabinets is more a traditional situation than functional one. Remember, many bedroom dressers have double handles(yes, I am aware the drawers are also wider) and are considered normal. Some of the objections also may have to do with how the person is working, often having something in one hand when opening a drawer for a pot/pan/skillet/etc. One example of this is the French door refrigerator. Transitioning from a single door(conventional or side by side) means changing the way the fridge is opened with something in a hand. Another situation is the way the drawers are built and how the glides are installed. Many newer drawers are not built as sturdily as they used to be and will rack more easily. Drawers with through dovetail construction are much more sturdy than half lap or similar style corner joints, which rely on glue and mechanical fasteners to make the joint. By the same measure, many glides are easier and smoother operating than older types. For myself, I'd rather have two pulls on a wide drawer then one big one. Esthetics.