[2bars]

I own a SPF, I picked it over the CSX for a couple of reasons. The first and main, was how I fit in the car. Hillbank has both in stock so you should test fit. The second reason, more of a bonus was the top, heater, defroster etc that came with the car.

In my opinion, if going with a small block and if you think CSX, then pick an FIA style, so it goes with the car, since you mentioned resale. I would think that a CSX 4000 with a small block would be like a three legged race hoarse. However the Small block in a SPF, no big deal.
There is huge price difference in building comparably equipped cars, and if your already thinking of selling before you buy, then look for a used spf for the least hit.
That being said, I have never bought a vehicle and used its resale as a deciding factor so my advice there would not be good.
I am also in Arizona. We have installers here.