If you are setting up a paint rig, then the most cost effective working
strategy is going to be a combination filter/regulator unit (called a
"piggyback" in the industry) followed by AT LEAST a coalescing filter unit, in
series. Minimum 5 micron filtration on the piggyback, and 0.01 micron on the
coalescer. That will take care of the oil and dirt. For water, there are a
few good inline desicant-type units that will work with low CFM's. A
refer-dryer is much better, but most start in the $1000 range.

If you're only going to use air tools, then the piggyback unit alone would be
sufficient. I would only add a lube unit if the air line its attached to is
dedicated to tools that require (the same) oil.

The best units on the market are made by Wilkerson, Norgren, and SMC. These
are REAL units that industrial machines use. BUT in your CFM range, they
shouldn't cost any more than the junk that Harbor Freight sells ($20-$50) If
you can't find an industrial pneumatics supplier in your area, try contacting
SEPA (South East Pneumatic Automation) in Atlanta. The owner is a retired
Lockheed engineer.

www.sepaautomation.com

That should do it.
Harry
former pneumatic industrial sales specialist