Stan - I'm a regular ebay shopper for all sorts of weirdness but have not seen anyone good for crotons. (I also collect croton picture postcards and croton postage stamps.)
For the cost of postage, a lot of members here would be glad to send you cuttings. You'd be on your own then, but there's probably a few threads and posts on rooting cuttings. It's not difficult at all - once the weather warms up or if you have a heated greenhouse. I know there's one croton head in the Houston area, but she has a greenhouse.
Recall that the croton really is a tropical plant. Mine here in the warmer part of St. Pete get fried every ten years or so. I'll have to dig out some old pics - it ain't purty.