Have you considered the rectangular AG pools? The Splash pools, while pricey, are a snap to install and come in all sizes. The hard part is getting a level surface but that's it. You can have a deck built around it.

Or there are the FantaSea pools--look like the old redwood pools, deck and all, but you'll need it installed. I have a FantaSea built into my deck. They are solar-heated as well.