When you do get a male (or any other new glider) there is no guarantee that they will not fight. Some gliders get along from the moment of their first contact, other gliders take a disliking to the new glider and it can take months of swapping blankets, pouches, toys, and even cages as well as many many supervised play times in a tent or bathroom before the squabbling ends and the old gliders accept a new one into their colony.
Any time you bring in a new glider to your home, there is always a chance you will forever have two cages and may need to try an additional glider to go with any single gliders you have.
Stick to your two girls and just enjoy every minute with them. If you want more gliders in a year or so, you might consider getting two more and introduce the two pairs. If you do that, I still suggest you have any males neutered. There are so many gliders already in need of homes that breeding just for your own personal experience is really not the best way to add to your glider colony.