Yes, you would need to use the single stack models of the TUFF Products 6 Inline Mag Pouch. MPN:7066-CBV-1 (Coyote Brown) or MPN:7066-NYV-1 (Black).
Yes, the single stack version should work for your setup.
Yes, the magazines will fit in this pouch and will have a little wiggle room as the single stack pouches are meant for 1911 magazines which are a little taller.
There are 2 sizes for this item. The smaller will hold Single Stack 1911 Mags and the larger will hold Double Stack Mags from 9mm/40S&W / .45ACP or Similar. The Velcro band is pretty wide so they may fit but they are not listed in the fit guide so it's not guaranteed to work.