You need headers to fit the chassis, therefore, headers made for 65. As Shagg said, if you're going to go to FI, you need Oxy bungs but stay away from the 94-95 FI set up. It's not as popular and the aftermarket is only set up t handle the 89 to 93 FI systems in early cars.
JBA makes excellent shorty headers.. that way you have no ground clearance problems. or, any at all really. i know ppl who run these and say nothing but good things about fitment and quality. you could also try hedman shorties they are probably about half or one third the price of the JBA's.