the regulator that comes on those compressors work fine with modelling. but I recommend getting an airbushing pressure gauge for it (about 20 dollars) ... the pressure gauge that comes on the compressor is graduated in 2 or 2.5psi marks, where the airbrush one is graduated in 1psi marks, easier to get the pressure right when you are trying for a low air pressure.
The water trap can probably be bought at sears too... also about 20 dollars, Lowes and Home Depot have them too... they are the same ones the hobby shops sell for more.
It's worth your while to get the water trap, before you end up with a blob of water on your fresh paint... I've done it... it's not funny!
Good luck to you! Mine is one from Lowe's and it's not too noisy that I can't stand it. One day I will probably get a modelling one, just didn't want to put out the big bucks on the front end as I had other things I wanted to buy too...