rubbing compound will work...but your gonna end up going over it again with a wax anyway to protect it from the uv rays.
Try a two-step sealer, they last longer than waxes (up to 3-4months), and have a light polish compound within to help rejuvenate.
If you don't own/have access to a buffer...good luck and god speed, lol. There's no physical possibility the human arm can produce enough friction fast enough to break down compounds to get them into the paint which is what brings the shiny gloss back.
If you'd prefer a hand method, try DER products, their a full chemical based polish and work excellent.
Painting your 7140 will look only as good as the prep work and time you put into it. I highly recommend going with a good epoxy primer, that makes alot of blemishes disapear. We painted our 7110 a few years back and we went with a higher end paint, but i dont think that is neccesary. A good omni paint will be just fine.