Why not neuter the males and keep them as a family? We don't seperate families here and the gliders are so happy as family units.
If you are going to sell them then interview the new owners, ask lots of questions, make sure any males are neutered before leaving so they don't become breeders who's offspring add to future gliders needing rescue. Have the people come for education and bonding time until the gliders, the new owners and you all feel comfortable. Go over everything from diet to health issues, make sure they have all needed supplies before the gliders leave. Don't trust anyone who gives you bad vibes. Also, have a signed adoption agreement that if they ever can't keep the gliders they come back to you. I would also add into the agreement that they can't be seperated, used for breeding, given away or sold just to be on the safe side.