Interesting idea. I've never seen anything like it before. For the water lilies, I'd say you'd need 18" to 24" deep. Small or dwarf varieties don't need as much space as larger varieties, so choose carefully. The other plants are marginals and the top of their pots should be 1 to 6 inches below the surface depending on the variety. If necessary, you can set them on some kind of stand to bring them up to the proper level. Drain pipes would be okay to change the water if you have a way of getting under it (is it a deck?). Standing water stagnates and will need to be changed occasionally, but if there are no fish in it, you can just put the end of the hose at the bottom and overflow it until the water runs clear.

Don't know if you have already made your decision, but I would actually describe the burners opposite of idrive65. Front to back to me describes the direction the burners run front to back with them left right and perhaps several in the center. That means that for indirect heat (slow cooking for ribs, brisket, whole poultry and large meats) you can use one or two burners on one end and cook on the opposite end, one on either end and cook in the center, use the center burner(s) and cook on wither side -- gives you options and full use of the front to back grill space. With side to side (not side by side) are burners going across from one side to the other where you have one front back and center. For indirect heat, your options are to use the back only or the front and back and cook in the center. You have the full width of the grill to cook, but less room front to back and the heat may be less indirect for whatever you are cooking. Webber has 3 different types of grates and different stores may carry one or two. Cast iron sears (may give a bit more char flavor) and retains heat well but rusts most easily (they suggest not cleaning after cooking so that the oils from cooking protect the grates until you preheat and burn them off when you cook the next time). Porcelain coated have protection from rusting, but some may feel they don't retain heat and sear as well as cast iron. We've used both and never had any complaint with the porcelain-- the rust factor probably makes it a better choice in our climate). Stainless is an option that comes standard on the higher end Summit grills or as an option or additional purchase for the Genesis. I've cooked on the other ones so long I wasn't sure about the stainless even though the rust proof definitely appealed in our humid climate. We were thinking about it when I realized the charcoal grills I've used all have stainless grates and the Summit ones were heavier and should do even better. So far, they've been working very well. I can cook happily with any of the grates, but the use of space -- having enough, being able to use it efficiently for large of small cooking needs and having it arranged well for what you want to cook would be what I would focus on. The burner direction matters most if you pile charcoal to one side and cook on the other. If you usually place evenly across the bottom, it may not matter to you at all. Have fun looking and hope you find one you enjoy.

Electric is quite cheap in your area especially if that is a delivered price(most utilities now price generation and delivery separately--the relevant cost is the sum of the two) Generally electric much less efficient at heating water than propane. Modern propane units would vent through a side wall with a PVC pipe. Need to locate unit in location which can run two PVC pipes to reach outside wall. If you can run plumbing to the crawl space, you probably can run vent line down there and then out to side of house (long runs require a slightly higher diameter pipe--not a big deal.) Cheapest way to increase hot water capacity: If hot water heater not cranked up to 140, raise temperature and add hot water extender valve to output of hot water heater (mixes in cold water to blend down to target temperature.) This can boost total hot water capacity a little--the hotter the temperature increase the tank can take, the greater the increase. Probably enough to solve shower problem. May not be enough for tub. In line heater as addon is interesting in that avoids some of the downside of inline heaters (lag turning on and not turn on if too low flow). Not sure why you would want two inline units--seems like a waste.

1. washer worked perfectly 2, Handy man turned off all water in the house. 3.Handyman changed gaskets on the outside spigot 4. Turned water back on to the whole house 5. Went to wash clothes and the hot water worked for awhile (5-10 minutes) the just stops. 6. Cold water rarely would fill at all. 7. Tried the washer many times but no luck 8. Handy man got the flood hoses and put on machine 9. Tried more times to wash clothes but water would fill for a few minutes and stop. The hot water would almost always come on for awhile. The only way the cold water would come on is if it was turned on VERY slowly and sometimes not even then. 10. Checked water at spigot - water comes out fine. Checked water from spigot to unattached washing machine end. Water came out perfectly. 11. Today, replaced flood hoses and put on the Eastman hose. Every single thing concerning water remains the same. 12. I have never, in the past, turned water on and off when doing laundry. It think that covers it. We did all of the GE testing ideas from Sammy above, All results are listed above.