I think they look pretty good. A few comments about the size:
1) If you made them 32" wide, then three of them would still fit nicely on 4 foot x 8 foot tabletop, which is a convenient size to make from a sheet of plywood.
2) 7" seems a little bit shallow - it gives you maybe 6" water depth max, but less if you are going to e.g. use eggcrate to hold frag plugs.