Any tank will work. The threads are standard threading.
The min/max output pressure depends on the spring kit and piston that is installed. There is a high output version and a low output version. The high output version works great for mags, but the low output version won't allow you to get to high enough pressure. Its not just a matter of changing the piston and spring. The back section is changed as well, to accept the smaller diameter piston for high pressure operation.
I don't think there is any difference between the 3k and 4.5k versions other than the safety pressure reliefs.
Except for the Automag in front, its usually the man behind the equipment that counts.