The Preval is a good way to go for the small job.
As far as jobbers canning product goes, it was more commonly done in the past than it is today, perhaps for air quality reasons. Check with your local paint jobbers. On the other side of the coin perhaps a cheapy or used gun might be the cost effective way to go. Then you have a one time use gun to set on the shelf beside all those other one time use tools. Impress the neighbors with all your "stuff"....
