I'm not quite sure what you're asking with your question but I'll do my best to answer it as many ways as possible. I feed my snakes f/t or live, depending. I also house mice in the same room with them at times, when my feeder-breeder rats aren't producing and my snakes eat fine every time with no issues. Are you worried that your snakes won't eat from being able to "smell" a mouse/rodent all the time and that will desensitize them to being offered food or are you asking something else altogether?
I have some rats that were raised as feeders that I have held back as pets but otherwise I'd personally steer you towards a crestie. Mice stink, BAD! and I've not found much of anything that helps with the smell. If you keep all of your pets/animals in your room, you might get tired of a mouse pretty quick once you've smelled them. If you have the time/energy/money to clean the tank/cage every day, you might be okay. Obviously the choice is yours, that's just my experience with mice. They and rats both can make great pets but mice reek with their urine and it doesn't take long if you have more than one for them to stink up a place. Good luck, whatever you decide and hope that helps.