I would like to get, for £80-£120 second hand a silenced/suppressed pistol for using with my pellet catcher in my flat.

I've seen a few online (one nice one that's a bit expensive), but don't know what to go for or how easy it would be to buy the silencer separately and add it to a suitable gun.

Needs to be relatively accurate, and the more realistic to the real firearm the better (it's just for fun). What do people recommend?