I agree with what Blaine's said for the most part....
Another thing to consider if you're thinking sand filter vs. cartridge is a drainage spot for your pool water when backwashing. For us, it's not a problem as we've got a small stream at the back of our property...but I've heard a couple of folks mention they wish they'd thought about where the backwash water will go.
I don't know what your budget is, but I can't imagine adding a deck-mounted fountain to your pool would add a LOT to the cost. When we've got those 100 degree-plus days, aerating the water at night will drop your water temp 3 to 10 degrees. We THOUGHT that's what we were getting with our pool, but it turns out our pb just gave us a cheap plastic fountain that installs in place of one of the returns. (So we can't turn off the fountain without either shutting the pump down or unscrewing it and reinstalling the return head).
If you don't elect to go with an Easytouch, and you DO go with the Intellibrite LED lights, definitely get the Intellibrite controller for them as well. Otherwise, changing the color or mode of the lights involves flipping a toggle switch on and off several times until you get to the desired setting.
We added an Easytouch to our pool, even though it's only a single body of water, because I wanted the ability to control the heat pump (adding it next year), lights, landscape lights (adding later), pump, SWG, and tanning ledge bubblers all from one panel. And, adding the Screenlogic option to the Easytouch panel gives you control of all of these things from an iOS device (iPad or iPhone). Is the Easytouch panel absolutely needed? Of course not. Is it convenient? You bet.
Our pool looks a lot like the one you're building!
