Kim, have you thought about going the silicon and resin route?
Sterling Supply is the place that I get my silicon and resin from. They've decent prices, and are real sweethearts to work with. They even changed up their shipping practices to allow me to remain a customer! They used to only send things out UPS, which for me is insanely expensive; when it came time for my second order, we were talking about the shipping and USPS Parcel Post was suggested as an alternate shipping method for me... so far it's worked like a charm! A little slower, but at least I'm not paying triple digits in shipping to get my supplies anymore. ^____^
The tin-cure silicon (just ask for the blue one) is around $100 a gallon, and white alumilite resin is about $115 for a two gallon kit. I normally get an extra bottle of silicon activator, since I tend to put in 15% instead of the 10% that it's supposed to take. Putting in extra activator makes the silicon set up a little quicker, though even then it takes upwards of 5-10hrs to cure.
If you've a pressure pot, pop the curing mold into the pot under 40psi for it's cure time (I'll usually leave it over night). Pressurizing the mold works just as well as degassing it in a vacuum chamber, and allows you to keep less equipment on hand. Once the mold is finished, pour in the resin, and pop that puppy back into the pressure pot for a pressurized resin casting. ^___^
Word of advice, never pressure cast in a non-pressurized or non-degassed mold. The resin piece will come out with random little spikes all over it! XD