One of the things that come to mind are Flair-It fittings, but I'd check with someone who knows what they are doing first. As an alternative, there are Sharkbite fittings, which can go from PVC to PEX, but because they rely on a single O-ring to keep water in (which gets eaten away by the chlorine in water), eventually those will leak or vibrate out. I've read about Sharkbite-like fittings that use two O-rings, but can't find a good source.
As an alternative to band replacement, would the Watts PEX Cinch Clamp fittings work? I read they are made from stainless steel, so I don't know if they are better than the aluminum bands.
The best route, IMHO, would be a replumb with PEX, and either Flair-It fittings, the cinch fittings that tend to be what most new RV makers use anyway (mainly because the stainless steel bands are cheap, and regardless of the pipe diameter, only one cinch tool is required), or if you have the money, PEX-A and expansion fittings which is considered the high end.
