Both of the below guns are short (as you seek), very accurate, eazy to adjust the power, both regulated, very good triggers (and adjustable}. Don't leak (mine don't !), overall, shoot well.
The Caiman is a bit nicer finished with a full covering wood stock. The butt pad adjusts up and down.
The Krait is much more industrial looking, with no wood. The butt pad adjusts both, up and down and in and out to adjust the length of pull.
Both shoulder and aim very easily.
I've got both models and like both models.
The wood stock Krait at the bottom has some good updates from the original Krait, but the regulator is not easily adjustable. It is a few dollars cheaper.
I don't have one of these...yet !
The AirMaks CAIMAN MK2 Airgun is not only lightweight but also comfortable to use. Its design is extraordinary, with a wooden stock that has an ergonomic, ambidextrous grip, a height-adjustable butt-pad, and a UIT rail for accessory mounting.
utahairguns.com
Or -
AirMaks Arms KRAiT Standard Bottle Airguns
utahairguns.com
Or - (a wood stock Krait), newer model of the above Krait.
Introducing the all-new airgun from AirMaks - the AirMaks KRAiT Lite Standard Bottle Airgun.
utahairguns.com
Mike