There's no suitable recommendation for YOU. You'll have to find what's best for you through trial and error.
What I WOULD recommend, however, is that you buy a good quality plastic or Kydex holster as a starting point, use it, and see what others are using, and try theirs, if they'll let you. Any of these shouldn't be more than $25 - $40. A Fobus, Blade-Tech, or Cen-Dex plastic/kydex holster is a good start.
I prefer "paddle" holsters for IDPA, but you may want one that attaches to the belt. A hefty "holster" belt is also recommended, even with a paddle holster.
I use a more-expensive Safariland holster for most of the guns I shoot, but "carry" in a tuckable IWB holster from a NC holster maker. I also have a very nice Cen-dex IWB belt holster I use from time to time, and several Fobus holsters.
The Fobus "double" mag, paddle mag holder (model 6900) is very good and relatively inexpensive. (Around $20.)