Do you mean the plastic/kydex stuff? Any mag holder for a double stack mag will take any double stack mag (and if it has adjustable tensioners, it will even fit fatter ones like Glocks). Otherwise, they will say "for single stack mags" which will fit the Sig 220/1911 style.
I've bought 5.11, Blackhawk and Uncle Mikes originally for all my 9mms (4 of them) and my Glock 20 and they all work just fine. I even competed perfectly fine for years in IPSC and IDPA and 3 gun. I've moved on to HSGIs now, but that's because I like gear; not because the mag holders weren't working well.