I think considering getting him a friend is a great idea!
Rabbits LOVE other animal company, mine are very bonded to my dogs and cat. But there is a special, unique bond they will form with another rabbit. Plus, it is just a terrific thing to have two happy bunnies living in your home.
Definitely wait a couple of months before even considering a new bunny.
Then make sure you have the time and space to do the bonding. (Two cages, or two side by side areas they can be in, I used a hallway and bathroom, and time you can devote to the bonding everyday, and then maybe a stretch of three or four days for a bonding marathon).
Then take your time. Search all of your local rescues, not just rabbit rescues, often pounds have rabbits in addition to cats and dogs. You can also search of rabbit adoption and your zip code and see what comes up.
Then take your rabbit on lots and lots of bunny dates and find a rabbit he is really comfortable with. This makes a big, big, big difference in the amount of time and effort and stress the bonding process will involve.
Good luck!