I personally don't like double stack as they widen your profile. There are several options out there that are adequate. Check out DS Tactical in New West BC, they are an amazing retailer.
I personally reccomend the HSGI Taco pouch. It can adjust to fit almost any pistol magazine, or you can get the longer ones if your mags are bigger/longer, etc. They don't come in a double pistol variant, but they are designed to stack and there's AR/pistol double stack variants.