360 build on a budget. Opinions????

I would build up the block stock (for now) and get a set of headers to replace the stock manifolds. Building up the motor only to choke its ability to get rid of spent gases is never a good idea. R/T heads on your motor might be a good idea too, if you can salvage a set, they breathe better. Cam and or intake upgrades would make sense later once the block is set up. By the way stock 360 motor in an early A make the car perform very satisfactorily.

Just my two cents