pritty much any reg will fit on pritty much any marker. generally the difference is if they need an asa adapter or not.
ive not met a marker that an angel air wont work with....that said they arnt the most reliable reg in the world but at the prices ive seen em selling for recently you cant go far wrong as there are loads of techs around that can help if you have probs.
if you have any questions i usually turn to tom allen on here for all things angel (althought there are loads of others too). he knows his beans and is always happy to help.