http://www.sdpc2000.com/
http://www.jegs.com/
http://www.summitracing.com/
These sites are online catalogs. The first site is a Chevy dealer. They sell engine packages to rebuild your block or the whole crate engine.
The other two sites have it all. Send for a catalog and get on their mailing list for specials.
Think about the way you will use your car the majority of the time. Call them direct they will answer a lot of your questions.