Dad's Fury's A/C isn't cooling too well. Put in a rebuilt RV2 3 years ago. And the guy that charged it (no longer in business) used R420a, RB276, & R22. Worked for 2 seasons.
Dad wants to start over with a Sanden pump.
Where to get a kit (comp., brackets, fittings, etc) at a reasonable price so we can use 134A?

3 well known.
classic auto air
vintage air
bouchilon(sp) performance.

any of those 3 should be able to get you an under hood kit.
if all you need is the compressor and mounting kit, I would expect it to be around 400 bucks at most.