I promised Kevin a full report. I received my k-bells last week from Detroit Barbell. They look really cool. There is something about forged steel that I just like. I have not loaded them up yet, but the hole is plenty big, and there are enough threads that the plug will stay put.
I bought a 6 inch with the 1 inch handle and an 8 inch with the 1 1/2 inch handle. I think the 8 inch is a bit big for shorter people, i.e. I think it will hit the ground on some exercises. I think the 6 inch is the perfect size for all around use, and I would probably get it with the thicker handle.
I like them and would recommend them.