I don't know about everyone else, but for my 1000amp attempt, I'm using TO-264 package 200v:
Digi-Key - IXFK230N20T-ND (Manufacturer - IXFK230N20T)
I like the idea of anodizing the heat spreader. Is it possible to anodize only part of something? Like the bottom 3/4 of it, so the top would still be copper or aluminum, and might carry the heat away a little better when it's in contact with the heat sink?