I have a 64 with the same set up. My plan is to go with headers and single 4 barrel. My plan is to use a 500 edelbrock. Unless you go with a bigger cam and headwork, the 650 may be too much carb. Contact Tom Langdon for any high performance parts, He is reasonable and you can get new stuff for what some people are paying on ebay for used parts. Check out the links section for his info. Good luck with the project.
James