I've got Blaster (retail) Boxes and some old Fleer, Topps and UD box sets that have Barry Bonds cards in them in my Ebay store and for auction....if you see something you're interested in let me know and we'll arrange a deal through Ozcards!!
I think Gary (Westriot) might have some MLB hobby boxes.
i usually get mine from dacardworld...u will see their banner at the top of the pages alot.
very fast shipping and good prices. i havent had a problem yet.