About 5 years ago, I painted 1/2 a motorcycle (long story, but I wasn't the one who crashed it (nor was DH), only the one who fixed it)
To do the painting, I bought a HVLP paint gun at Princess Auto, our equivalent of Harbor Freight. It was about $20, iirc. At the time, the next door neighbor was a licensed bodyman. He looked at the gun and figured that it was a professional gun, but refurbed. I used the gun with the air compressor we had in the garage, about 9 CFM, barely enough to drive it, but all it really meant was that I had to wait for the compressor to charge back up quite often. Motorcycle plastics take a lot more time to paint than any sewing machine, the compressor wouldn't have to have a huge tank (which seems to be what drives the cost up), just the ability to drive the gun (it would have the requirements on the package)
As for removing the existing paint, Dave McCallum has a bit to say about that:
http://www.featherweight221.com/fwrx...95046357133719
I'm going to try to take one of these on in the next few months. I have a featherweight that's been in pieces for months waiting on paint. The decals are here, the replacement parts it needed are here. It's all sitting in the sewing room looking forlorn. It's about time it became priority.