I know there is a company called "Coy's" (coyswheel.com). They make billet rims and they are cheap. I don't know how good they look in person. I also don't know if they do custom offsets either.
Most centerlines are forged if its not in the billet category and the billets they offer go for around 500 a wheel....you wont find cheap new billet wheels just wont happen. Billets are in a category of their own in prices