AirForce TalonP PCP Air Pistol, Spin-Loc Tank
Thanks to the new Spin-Loc tank and collar, you don't have to remove the gun's air reservoir to fill it. Of course, if you want to, you can remove it easily and attach another one. Carrying an extra filled tank when shooting in the field is a lot easier than carrying a scuba or carbon fiber tank for refills.
Most dot sights have Weaver mounts. If you choose one of them, remember to pick up AirForce's 11mm-to-Weaver adapter listed in the accessories link.
The AirForce TalonP PCP pistol is heavier than most air pistols and cannot be comfortably held the way most pistols are held and still result in reliable, repeatable accuracy. A comfortable hold is with one hand on the pistol grip and the other holding the top of the scope. If you assume a sitting position, you can hold the grip with one hand and rest the gun's forearm on your off hand's forearm. These two positions will draw the pistol much closer to your eye, and you can mount a rifle scope on the TalonP air pistol. A pistol scope could also be mounted, but there are more choices among rifle scopes.