I agree with Goat. I just put together a pressurized system, and I love it. I have only had it running for a couple of days, but it is doing wonders for my tank. Overall, I enjoyed putting the system together, and the guys on here are really helpful when it comes to questions. Check out the primer, and there are a few other helpful regulator build threads.
If you don't want to put one together yourself but think you might want to buy one, I would suggest asking around on the forums. There are guys around who might sell you a unit.