They don't necessarily NEED a friend if you are giving it the proper amount of socialization, which from the sounds of it you are. Giving him toys and stuff will also keep him entertained.
The best thing you can do is continue to socialize with him, get to know him, and do the best you can. If you see any signs of depression then get him a buddy or a new home. Until then he should be fine by himself.
By signs of depression I mean he's lethargic, not eating, over grooming, doing repeated actions, etc. And by repeated actions I mean things like going to the top of the cage and throwing themselves to the bottom then repeating, or running endlessly around the cage in the same repeating pattern.
And btw no, I personally do not have good stories about single gliders.