There are lots of reputable breeders out there. If you find a snake you like, you can ask around to find if they are reputable. Fauna Classifieds board of inquiry (BOI) is quite useful.. you don't have to be a paying member to search the archives.

Other species to consider:

carpet pythons (jungle for color, coastal for size)
blood pythons (sumatran red and sumatran short tail [black blood])
dumerils boa
argentine boa (boa constrictor occidentalis)

Oh.. and I'd start with a 20 gallon size cage. A full grown red tail would need a 4-6' cage. Some smaller males will stay on rats their entire life.