I researched for months and this is what I settled on. I have one of those Polar Air 10 hp 4 cyl uprights, and when talking with the owner of the company he advised against getting the 175 psi option because it cuts cfm. I went with the 150 psi setting and have enough air to blast using a large Texas Blaster pressure pot with a 3/4" i.d. hose and a 1/8" nozzle opening.
CFM is more important than the pressure. Our blaster is set for 125 psi.