I purchased a Daystate 2 compressor from AOA in december.
It is a great compressor, and it takes about 5 minutes to top off either a SCBA from 3000 to 42 or 4300 psi.
5 min to top off scuba tanks 2400 to 3200.
I am also a diver so I wanted a good compressor with dry air and min time to fill the tanks.
The Daystate 2 is that compressor.
There are other options (less cost), compressor allows you to shoot as much as you want without being concerned about running out of air and the problems/inconvenience of finding/going to a shop somewhere.
A serious air gunner should have his own compressor, and being a diver as well it meets all my requirements.
Todd at AOA is their compressor Guru, a good guy.
Discuss your requirement with him.