Normally I would say stick with the OEM CZ mags, they fit and function perfectly, but after one of mine cracked at the feed lips I'm not so sure. I did switch over to PSA mags and they have been pretty reliable and relatively inexpensive, but I'm not so happy with the fit of the PSA mags. It seems most of mine need some filing in order to make them fit, and even after that they are tight. Also, the last round open feature isn't reliable. Probably a little more fitting here and there would make them better, but I don't think all that filing and fitting should be required on a quality magazine.
I recently ordered a couple of Magpul mags and although I haven't had a chance to go to the range and try them out, so far I'm impressed. The last round open feature works every time and the fit is perfect, not too tight, not too lose. Plus they practically shoot out of the mag well when you press the mag release button.
It seems it isn't possible to get all of the features you want in one magazine. The PSA mag has metal feed lips which should help in longevity, but in my experience, they require filing/fitting to work properly. The Magpul fits perfectly, but it doesn't have the metal feed lips. Neither do AK or AR Magpul magazines and I've never had a single problem with them so I don't anticipate any problem with the Magpul for the Scorpion.
So take your pick.