Garters don't have to eat rodents. They can live on a diet of fish, earthworms, and/or amphibians. Just make sure you choose the right kind of fish (thiaminase-free) and add some reptile vitamin/mineral powder to the worms. You can even use fish fillet (again the safe kind) instead of live fish (vitamin/mineral needed every few feedings). Garters are about the same size as the snakes you're looking at and some are very easy to handle. If you get normal colored garters, you can find relatively inexpensive captive bred snakes. Of course, I may be biased toward garters......