another way to paint if you don't have a proper air compressor is PREVAL sprayer.
they are just like a DIY spray bomb. there is a compressed air canister on top and a glass jar at the bottom where you add your own mixed paint. then the compressed part sprays out your paint just like a spray bomb. when you are done you clean it like a regular paint gun and it's ready to spray the next job.
i have used theses sprayers more times than i can count over the last 20 years and they work MUCH better than the average spray bomb. they are probably MUCH cheaper than spray bombs in the long run.
they are available at any quality hardware store. ALL of the major chains carry them in their paint department.

Preval spray system.