Yes its a great site. Has helped a lot of people out. Kal is an e-god! And yes you will need a heat-sink, not for the contractors but for the ssr's, they put out a lot of heat. But as for your contractors, don't go with the crap ones on ebay. Stick with a name brand, I think I have a several left over for my e-build. I'll look when I get home. They are quality Allen-bradley, and if I do have a few Id be willing to part with them cheap to save you a few bucks.