Someone posted a link for a Siamese rescue service recently:

http://co.siameserescue.org/

Presumably their cats would be inexpensive, if not free, and they might
even have homeless kittens. They have a map showing what areas their
volunteers cover under 'Meezer Express' and then click on the map. Due to
them not having labelled the states, and my poor knowledge of American
geography, I can't say whether this coveres Nebraska.

You might contact www.thecathouse.org because they do occasionally have
rescue purebreds. I know they had an adorable oriental who was adopted out a
few months ago.  I would also call around to the vets. Definitely ask at the
All Feline Clinic. Often they know of someone looking for a home (I would
exhaust siamese rescues first. I just bet there is one out there.) I
actually have not seen any Siamese breeders around here. The only purebred
breeders I ever see in the area are for Maine Coons (several of those) and I
think maybe a Devon Rex breeder nearby. But I think it possible you could
find one through the Cat House or Dr. Arnold.