Tactical Tailor Fight Light MAV 2-piece, with possible addition of the short Fight Light X Harness for comfort.  I'm assuming your water will be carried in your pack, so the long X Harness, more suitable for direct attachment of water bladder carrier, is contra-indicated.    

Or something close to the above from another mfr, perhaps ATS, to name just one.  Select single or double mag pouches to suit.
 
You'll need something fairly wide in order to carry 4-6 mags plus IFAK and comms.

The Army or USMC Tactical Assault Panel would be large enough, but not split front.  It would be OK if you are using AR-type mags.

The smaller rigs, such as the TT Mini-Mav, are probably too small for your as-stated needs.

I suggest you give some thought to configuring your rig for enhancing the ability to low-crawl, which means as little bulk on the front as possible.  That, and ease of donning/doffing serve to indicate a split-front rig as optimal for your purposes.

I would also highly recommend that you give considerable thought to your selection of footgear.  An ounce saved on the boots is probably equivalent to a pound saved in the pack at the end of the day.