Any glue will work, but I always recommend loctite gel superglue,.. its great stuff. And yes, priming is a good thing. In fact, prime the pieces then inspect under a bright light,.. this should make any flaws/imperfections show up. (Pitts, gaps, mould lines, etc,...) sand, fill in, otherwise fix the issues, then reprime and recheck. Take the time to dry-fit everything,.. I guess my best advice is DO NOT SKIP ON THE PREPWORK!!! If you don't solve these issues up front, they WILL show up in your final product. I also recommend painting seperately and assembling later when/where possible.