Why not take your time and find one that someone has already spent some money on who is ready for a new toy?
You might find one with heads, cam and intake, and the ALL IMPORTANT forged pistons with a stronger bottom end.
I can tell you from experience that any turbo system will eat up any 302 that is not prepared for it. The kit you reference especially. 5-6 grand would be a start. Now a supercharger setup would be in that range, say a Vortech or ATI, plus the stock computer will be able to be programmed for it much more easily.
The 302 computers have no idea when a turbo asks for more fuel, but superchargers are linear to rpm and fuel is mappable.