318

Yes, I would degree the cam to make sure it is right. With a 318 I would go milder, maybe a 268* max cam and that single plane is going to kill your low end torque. Spitfire or Laysons headers should work on a 318 pretty well and I think they are around $500.
I agree, pushrods will have to be custom and I like adjustable rockers, even the old 273 style rockers work well.