Wagner has 4 units that are suitable for this application. There may be other companies that would have something as well. Check out the following links. The Fine Spray unit is the cheapest. If you see that you are doing more volume or you just don't like it, look at one of the others. They are for more constant use.
http://www.wagnerspraytech.com/Wagne...ode=Fine_Spray
http://www.wagnerspraytech.com/Wagne...=FineCoat_2000
http://www.wagnerspraytech.com/Wagne...Code=HVLP_2600
http://www.wagnerspraytech.com/Wagne...Code=HVLP_2900