I have two of these one 9mm and one 40 cal , almost all parts including mags can be ordered from eaa , have found it to be one of the most accurate pistols I have , it outshoots my colt national match , I think you will find that if you change the recoil spring to a slightly heavier spring and consitantly shoot the same weight round you will be ok as far as the hitch you have with the slide in recoil , it was designed to be a race pistol and therefore has to be tuned to your load , you can change the recoil spring and or the hammer spring and accomplish just the right combination , just be consistant in your load and you will find its an excellent pistol , I wish springfield still made them .
they were made by tanfoglio and assembled by sprinfield , eaa tells me their slides will fir as well as their barrels , I know that their sight's and mags fit as I have done both . good luck