Howdy
I have a 38 super MKV.Detonics 38sup mags are VERY expensive IFyou find them. As Rick said, any mag that works for a 38sup 1911 will work for your gun. just be carefull reloading from slide lock as the mag will contact the ejector first and if you slam a mag in hard you stand a chance of breaking/bending the extended ejector. I have been toying with the idea of cutting and rewelding Colt/Mecgar mags to make them fit like a stock mag but I just haven't got around to it yet. I'll let you know if it works out.
Hope this helps!
L8r
conley

PS I have found that the 38supers are not nearly as friendly to shoot as the 45ACP combat masters.