If you don't plan on going over 600hp then I'd go with FAST's EZ-EFI. It's a rather simple system, that you can get complete for under $2,500. It's a very clean install, bolts onto a carb intake, and with a few basic setup parameters you're off and running, and it tunes itself. No tinkering needed, and you could probably swap from a carb to that setup in a couple hours. The most complicated part of the installation is welding an O2 bung on the exhaust, otherwise it's pretty plug n play.

I'm seriously considering running that setup, as it has a lot of advantages carburetors do, the only thing that makes me hesitant is if I build something later off an aftermarket block I'll go for more than 600hp with a blower, which would make the system useless if FAST doesn't develop bigger injectors for it(which they probably will at some point). You basically tell the computer what you want with that system, and it reprograms itself to achieve it.

 

With it being a 65, I would stick with the carb.
Also carb = more horsepower!