I suggest getting one that has 2 heads on it. The silent ones are amazingly quiet, but they don't seem to recover as fast. We use a single pump/head AMS unit (AMS # CM50, 6 gallon) to power our Wizard and AMP Vnailer, and it keeps up fine with those two items - because of their low air requirements. This model has an air filter on the intake, and a (pc type) cooling fan for high use applications (we have our cooling fan turned off, because it never gets hot enough to need it)
When they say SILENT, they mean it. This thing is so quiet, we could literally put it under the front counter and no one would know it was there. It's so quiet that you have to put your hand on it to verify that its running. The cooling fan is actually louder than the compressor.
We picked it up last year from our local supplier, Don-Mar, and it was in the 800-900 range. We're very pleased so far.
Mike