I would do neither. Not even PSS. Last time I was fitted for my irons, I went to my local pro shop in Mineola NY, who is highly regarded(even before they made it to the Golf Digest list), and also does fitting for PGA amateurs and other professionals. It took a few hours. He doesn't display clubs and doesn't have all of them. It took my measurements for length and grip size. Then he has heads to attach to different shafts. Decided on which heads I hit best by the tape method. Then hit using a monitor to display which head was better for mishits, and dead on hits also. Then tried many different shafts using their shaft monitor, deciding on flex, weight, kick point, etc. THen sent the specs to Mizuno to build my irons and wedges. They shipped them back and the fitter double checks the lofts and lies before he called my to pick them up.
When I finally/hopefully get another job, I will go back to them for the new Mizuno irons. Maybe a driver and 3 wood too. He isn't cheap, $125 for the fitting, not deducted from the cost of clubs. Yet worth it.