I was in the same situation and painted my aluminum sided Starcraft. I do residential and light commercial painting so have a Graco airless sprayer. You can rent a sprayer at any of the paint distributors (SW, Benny Moore, etc.). You don't need a compressor and HVLP spray gear unless you decide to do an automotive type finish. IMO, those aren't necessary and would be a waste of your time and $$$.
Here was the drill: Clean aluminum siding with a strong cleaner (IIRC, I used a siding cleaner). Scuff surface with 3M plastic pads using Jasco Phosphate substitute prepaint cleaner (important to use an anti=oxidant cleaner). Clean surface with the Jasco and rinse. Tape and mask everything you don't want painted. I sprayed a complete primer coat on the siding since I had a few bare spots and I wanted good adhesion. If the siding still has paint, you don't need an etching primer. I used Sherwin Williams Industrial DTM primer. Finish coat was then sprayed using a latex enamel. The accent stripes were painted with rattles cans (Rustoleum, some type of metallic bronze). The paint still looks good going into year three.
