Post a want ad here on the LilBeginnings Saleboard. I see lots of creme based colts on there.
Also, start checking out some farms that you admire. Arion Mgmt and Little King Farm has lots of double dilute colts each year, you can get a young one or ask if they have any clients with mature horses for sale.
With any horse, be sure you buy the HORSE you WANT, don't be suckered by big farms. Not all big farms will overcharge you, you DO sometimes get what you pay for. Yes, there are good deals and SOME small farms will have equivalent quality, but either way I suggest you get a couple people who are experienced with the miniature horse industry to ask opinions about possible purchases.
Good luck,
Andrea