best compressor?

yes, a single 480 would work fine on 5 gal.

i have viair 480s..and an 8 gal tank....they work great, and i love them...

how much better is the 480 than the 380 or 400?

I found that once you try engine driven, you dont go back. Once I got one in my mazda I dont think ill ever go back to electric again. Except maybe in my Datsun 320, cause I dont think 60HP would be able to turn over one of those.