Of course two is better than one. Just like three is better than two... and so on..I am in the process of trying to convince my husband that we need one more cat.....we have one right now. She's 15 weeks old. I found the cat I want at PetSmart (through the humane society). He's a 1 1/2 year old brown tabby....just a typical looking cat but his personality is so awesome! I'm not one to care what a kitty looks like, I watch for the personality I'm looking for.
How many cats do you have?
Are two better than one? I'd have to think so.
Seriously though. Two is better especially when they are young. They have each other to burn all that excess energy off with. It's also nice that they can grow up together. I agree with @Kieka about an older one. The kitten would probably be fine but a lot of older cats don't tolerate all that unbridled energy well. Some do and some don't. I'd really go with a kitten of a similar age.
You'll just have to tell hubby that he's been outvoted and that's pretty much that.