Guinea pigs are social animals and to leave them alone deprived of other
cavies is just plain cruel.
It's really not hard to do a proper intro. it may be hard at first since they often have "scrabbles" but unless blood is shed you shouldn't seperate. intro on a large territory that neither has been on before and include lots of food and hay in to different spots.
As for the cage, you should do a complete cleaning. Soack everything in vinigar or just go out and buy new things (if possible). And remember, the bigger the cage the more likely the two males will get along. For two males who almost never fight, a 2x4 is reccomended. OOf course, a 2x5, 2x6 & a 2x7 would be much better.
If your really worried about getting another male, why not have your oy nuetered by a
cavy savy vet so you could adopt a female (since they almost
always get along) or look for an already spayed female. A spayed female is rare to find since it's a risky and more invasive(which means more expensive) surgery.
Also, I'm sure you already know this but please adopt.
www.petfinder.com Guinea Pigs Social Life Pet Stores and Guinea Pigs