Put up with an oil-less 3/4hp portable racket-maker for years until all the pieces finally came together for this project. Brewed up from a $60 NOS (new on shelf since 80's) Quincy X8 pump off eBay and a $90 used Baldor 1hp motor. Already had a really excellent Lytron heat exchanger coil that had escaped the periodic dumpster "consolidations" for a few decades (originally aimed at a solar project), so I got a pair of 220v fans (again eBay, $65) and formed up a proper mating plenum for the Lytron to make it all look and work like a real "downtown" after cooler. The back end of the air manifold goes through the wall to a 120gal galvanized, heavy gauge well tank I have used for years with the portable. Now all is nice and quiet as she putts along, can't even hear it outside the garage, and it delivers about 3.5 CFM running at rated power. Only trick other than selecting the proper motor pulley and a power factor correction cap to run at rated power and minimal current, was to add pulse dampening for the pressure switch and main gauge since I really didn't want to run a second line out to the tank just for the pump output. All in all, well worth the time and money, wish I had done the upgrade about 20 years ago.
Edit: Just for kicks, I added two pics of a redundant air plant I built to power the pneumatically lifted glass panels at a high-end watch store in Manhattan a couple years ago. Converted the whole store from a Far East designed and made, Ho-Chi-Min gear motor, cable and pulley nightmare, to a simple, reliable ingenious American pneumatic solution. Due to unattended location in plenum space and mission critical nature (A flagship Longines store), fully redundant air plant with little rocking-piston pumps, dual check valves, dual switches, etc. was in order. I was originally going to use one of these little pumps for my garage, but they only can make 90psi at minimal CFM... very quiet and reliable but even with a 120 gal tank it's just too small.