This is the pistol variation of the rifle Riverview Sporting Goods
Not too many of us here are familiar with this. Regarding mags, I would look at CDNN.
I might suggest a suppressor.
I will say, do not put a vertical grip on it. I believe that would be illegal.
I picked up a used mint example this winter but beings as I'm in Maine and it's to cold to shoot I haven't tried it yet. If it's half as much fun as my rifle though, it's going to be a blast! I added a holographic sight, folding sights, and rail protectors and it's a cool little gun. As was stated, don't put a vertical foregrip on, thats a big federal no no.