Hi Jess' Mum,
I have two at the moment, brother and sister, had them since they were kittens though, and they adore each other!
I don't know what I'd do if I only had one because my two play together constantly, go to sleep together, everything.
I've got a new arrival coming on Saturday, so it will be interesting to see how they take to him, excited though!
Good luck, but I would say it's a good idea, probably better getting a younger cat too, because Jess is only 10 months he would probs enjoy someone to play with, which might keep him out of trouble haha..
Sarah x