Hello and welcome! There is no better place on earth for chinchilla info, so it's good you found us.
I am cautioning you against a second chinchilla, especially if you don't have much time for the first one. I'll give you two case scenarios:
One: My friends had a chin for a bit and then got a second. They don't have much time for them either, and don't let them out for playtime.
They thought they would amuse each other. Well recently, after about a year and a half, the chinchillas have started fighting. Their original guy is getting pummeled by the newer guy. He has tattered ears, and has become completely anti-social. They've had to separate them, and now they have two lonely chins in two cages that get little-to-no attention. It's very sad.
Two: I got a second chin after a while and immediately they didn't get along. My first chin is too territorial, very bitey and very happy to be alone. They just attack each other when they are allowed out together. Now I have two cages side by side, and they can only sniff at each other from their cages. It's twice the work (mine DO get let out almost daily, two times the play time), and cage cleaning is a pain in the butt!
I guess the moral of both these stories is be prepared to have two cages and twice the work, if you get another one and it doesn't work out.
My suggestion, if you are worried about one guy being alone, is get a nice big cage with a flying saucer wheel, and spend some time making some fun play toys for him. They aren't lonely, they just get bored. Martin's cages are awesome, and huge.
Martin's CagesBesides, if you get another chin, they realize you're not a chin (or that they're not a human) and they will not interact with you the same way anymore.
Regardless of what you decide, good luck!