if you think you're definately going to buy an fd3s, then i suggest you become a member of the rx-7 forums
nopistons and
rx-7 club. i prefer nopistons. they're nicer to the newbies anyway, but rx-7club is much bigger. ask a lot of questions about buying one. i wish i had done this before i bought one. it would have saved me thousands. also,
this is a good site to read up on about rx-7 faqs and how-to sort of stuff. good luck.