Yikes! I would be nervous about that (sorry, not trying to be pessimistic, just being honest) is there someone you could hire to come into your home so Peanut could be in familiar surroundings?
If not the things I would look for is that rabbits aren't housed/boarded where they can hear dogs barking or cats meowing. Could be stressful!
Also, how long are they alone for? Overnights? Weekends?
I would also ask how familiar they are with rabbits and their care.
Good luck!