I don't think anyone has anything other than anecdotal evidence to support the idea that a black car gets hotter than a white car, per se. The thermal properties of a material, emissivity, etc. aren't necessarily color-related. I'd say you should just buy the color you want, and stay away from a full-leather interior (sounds like it'd be a pain in the butt to keep it properly conditioned out where you live).
In some countries, Porsche still offers a tint on the top of the windshield, but that's about it. Not here, as far as I know.
I've found the AC to be very good with the top up, less so with the top down of course.
