Regarding insulation, http://www.fsec.ucf.edu/en/education...ingSystems.pdf says that conductive heat loss to the ground is extremely small compared to other losses. It's generally not worth the cost. However, you can get it if you want it - look for a dealer that sells insulated-wall pools like http://www.radiantpools.com.

I'm in northern VT, and I skipped the insulation. Can't tell you how good a choice that was, because we're still building