A set of rails with custom brackets only runs $200 on etrailer, and I installed mine myself in an afternoon. I use a rail mount Andersen and I love the gooseneck style smoothness and performance over rough terrain without the downsides of a gooseneck adapter on a fifth wheel. I do prefer a rail setup (or pucks) to the turnover ball systems but you'd probably be fine with one - the reviews I've read on them are overwhelmingly positive.
I haven't used an air style hitch so I can't really comment on how they compare, but if that's the way you want to go I wouldn't let the rail installation dissuade you - it's really an easy job.