Thinking about adopting a companion for Rio

I have been debating adopting/rescuing a companion for Rio, he is a two year old light ebony chinchilla. He gets really lonely and bored at times. I play with him and let him run around the room every day and he has tons of toys, but he still seems bored. Here is the problem though: I'm not sure what kind of chinchilla I should look for to be his companion. Awhile back I rescued a 7 year old standard gray and I couldn't even keep their habitats in the same room, they loathed each other and would do just about anything to get my attention anytime I was near the other. I ended up giving Clyde to my sister because he started to get mean after being housed near Rio. I don't want another dilemma like this, all I want is what's best for Rio and I don't want him to be lonely. Is there a certain breed/mutation of chinchilla I should look for? A certain age or gender? And how should I go about introducing them?



Thank you,

Jaz