How much movement do you want?
If you want a lot of movement with some protection i would go with Paraclete Hard plate carrier or chicken plate carrier.
Paraclete HPC
http://images.google.ca/imgres?imgur...%3D18%26um%3D1
Chicken Plate Airsoft replica
http://cgi.ebay.com/TS-Chicken-SAPI-...item2a02281c29
Both these rigs make holstering on the belt easy as there isn't anything there to obstruct your holster.
If you plan on getting the MBSS, I would suggest the S/M sizing because the one in Shell Pants post is of a large and usually worn by burly Navy SEALs who's shoulders clear the shouldering of the gun lol. The medium Size is angled off at the shoulder so it will be easier to shoulder your gun. This item can be had from Pantac at a cheap price think it was $80 dollars?
If you want a little more protection with lots of movement in the shoulder I would also suggest the LBT 6094 which is basically a Plate carrier with a cumberbund for extra real estate for goodies. Pantac also makes a knockoff of this so you can save dollars here as well.
In terms Gear bag there are few out of there that are good, but the one i enjoy most is this Eagle Sigma III bag, that comes with the padded M4 Case and shoulder strap.
http://www.optactical.com/easiiiibagwp.html
I own a lot of this stuff Tyson, so if you want to copafeel your welcome to.