I have a hard time seeing the cummerbund being useful, there's only about 15cm of open space with no MOLLE on either side (and I'm fatter than you, too, FOX). The whole reason I like the setup is because I don't feel all Michelin Man but retain lots of MOLLE real estate.
If you're really keen on having a setup with an optional cummerbund, go for the plate carrier instead:
Unless you really want the ability to use it as a chest rig, too. But the PANTAC one isn't comfortable at all as a chest rig (I've tried a real Eagle RRV and it wasn't a problem, so it really is the foam PANTAC used. I'm working on a full review.)