I would go with Wes @
http://www.classicheartbeat.com/ for parts. He uses the best stuff and has the experience to handle your questions.
As far as antique insurance. I would go with Haggerty, judging from my research and their willingness to actually pay their customers. Figure on aproximately 100$ per year for each $10,000 of stated value, which is cheap. The amount you decide on for coverage should be based on replacement value, so thats up to you.