[Bones]

Some of the items such as fittings could also be found at places that make hydraulic hoses since many do more than just that.
We have one here that if it's related to moving air or liquid through a hose, they've got it or can get it.

Really need to pop in one day and score some barbs for my setup......

Grainger is a great place and would probrably have what you need, other places such as MSC or Noland could have this stuff too (Not sure if Noland is a nationwide company) but here they carry most anything you could think of related to stuff like pressure switches - That's where I found the pressure switch for my well pump when no one else seemed to have it.