For CQB, I'd imagine fast reloads would be important, so you'll want open-top single mag pouches. It can take an extra few seconds to open a flap and pull out a mag that's sandwiched in next to another mag. A dump pouch would help too, so you don't have to fumble around trying to stuff empty mags back into pouches.
As far as which vest to go with, what's your budget for complete vest with pouches?