68/4500 is usually the most common tank, it also has the best resale value as well. BUT it depends on what you need for the marker+tank+hopper combo. You need it to feel natural and basically a part of you then you'll be a much better snap shooter and have much better marker control.
Scenario or airball??? If senario how long? If air ball what position. I have a 68 4500 psi it is a good amount for a back player which I am. Also if you play long scenario matches good for that as well.
