I have 9' celings. I have 18" between the counter and uppers (= 16" betweeen counter and light rail). On one wall I have 42" cabinets, minimal crown and open space to the ceiling. On the other wall I have 42" cabinets + 12" stacked above it, and a minimal crown. I like the look of the two heights, and it worked for my kitchen - if my kitchen were smaller, and I needed every inch of storage, I would have done the stacked 12" cabinets on both sides. I chose the 12" stack above the 42" cabinets for the following reasons: (A) a big crown is just not my taste for a kitchen, though of course your taste and decor may be different (I love big crowns in libraries and dens though), (B) wanted the extra storage of the additional 12" cabinets, for things like holiday decorations, and other seldom-used items that I nevertheless need to store somewhere, and (C) didn't want the look of 48" uppers + crown; I just simply preferred the look of the stack, plus I wanted some separation in my cabinets from those seldom-used items I store in the 12" uppers. HTH.

In a previous kitchen I had 8' ceilings and I squeezed 42" cabinets in, with minimal crown molding. It meant I had to shorten the space between the counter and the bottom of the upper cabinets. The plus - the tall cabinets made the ceiling look taller, and the kitchen larger. It was quite a remarkable effect. The minus - what I mentioned about the shorter distance between the counter and uppers, which I regretted. Live and learn. Not only will stacked cabinets under an 8' ceiling visually negatively affect the feeling of openness and height, as Sophie and others pointed out, but you will also be foregoing shelf space. The stacked cabinets will force you to lose at least one shelf's worth, or maybe two. Given my experience with my last kitchen and its 8' ceilings, I would get 39" cabinets, 3" crown, no stacks, and thereby get the feeling of height I mentioned. You won't be compromising on the space between the counter and uppers--which should be 18" BTW. You won't lose shelves either. It will cost much less than stacked cabinets too. A win-win-win.

Another option to consider, if you don't like the short cabinet look, is to split them differently--we have 18" over 32" with 9-foot ceilings, for instance. We considered 50" single doors (and also 48" single doors with extra moulding) but didn't love the look of either for our particular space. I've seen other kitchens where it looks wonderful, though (and some people do a false split where the door has two panels, but is a single door). I sized our cabinets to be able to just reach the top shelf of the lower row without a stepladder; I need a stepladder for anything in the upper row. We use those for long-term storage and I really love that solution after several years in the finished kitchen. It's nice to have the two spaces compartmentalized. Ours have glass doors in the upper row and solid doors in the lower row, since we use that for food storage. A lot depends on how you plan to use the storage, though. I did line up our fridge cabinet with our top row of uppers and really like how that turned out, too. (ETA: We put an adjustable shelf under the fridge cabinet since we also have a shorter refrigerator but planned to replace it in the not-too-distant future--so the cabinets still line up, but the shelf can go up and down based on the height of the refrigerator below. It makes the space look finished while not locking us into any particular dimensions--motivated by the fact that our 1940s too-small fridge enclosure was one thing driving our remodel!) This post was edited by artemis78 on Sun, Jul 20, 14 at 2:09

There are plenty of semi custom cabinets available that offer a standard "stacked" wall cabinet- with one long and one short section- typical 45 and 48" total height-top opening of 12" 48 brings you to 9 1/2 ft nominal, leaving 6" for molding which is nice for a stack of molding. For instance looking at Showplace a stacked 3648 is about $215 more than a simple 3636 wall. Many brands that don't have a standard stack will "combine" cabinets - you pick the sizes(which will be available from 12-42" high in 3" increments) and they make them as a single cabinet. Costs doing it that way vary from brand to brand--from slightly more to quite a bit.