Pellet Pistols
Think you will find a good old rifled barrel lead pellet pistol will be far more consistent than a typical lightweight plastic (6mm) pistol.
As said the CP88 pellet pistol is very capable, provided you handle it accordingly. That means avoiding movement of the muzzle at the trigger release (whether in SA or DA).
PCP pistols will typically not only give you more oomph, but typically better mechanics, in particular a very refined and smooth trigger release. But note that some C02 pistols are also VERY capable (SMK CP1, Tau 7, FWB Mod 2 amongst many others) without the need for an HPA cylinder.
Treat Others As You Would Wish To Be Treated.