SKD PIG Brig CR setup question

Background: I'm a civvie who needs something for rifle and shotgun classes that is a little more modular than my old trashy Blackhawk cross-draw vest. I am a big guy (5'11", 235lbs), and not in the good "barrel-chested freedom-fighter" sense. I don't know anything about gear other than attaching a good holster and mag pouches to a stiff belt. :p

I originally was leaning towards plate carrier, but I was told those flop around without plates in them, so I'm moving in the direction of a chest rig. The SKD PIG Brig CR seems nice in that it's light and modular, and the CR modules are still usable if I step it up to a proper plate carrier setup in the future. If I'm understanding this correctly, I need to buy the SKD PIG Brig CR of my choice and a harness set. I like the ability to have a back hydration carrier for outdoor classes, so I'm leaning towards the load-bearing harness. Am I missing something? Is there a better value system I should be considering? (I've been told about the Spiritus, which also looks good.) Thanks for the advice!
A much better system is the Velocity LEPC and LWPC. Not only does it interface with swift clip systems, which is becoming the industry standard, instead of the PIG only setups it has the benefit of being sized for SAPI size plates instead of 10x12. This is important because longer plates provide better protection of organs. I really like my Mayflower gen IV chest rig. I also have a BFG ten speed M4 chest rig which can work with swift clips and buckles. I use it mostly as a light weight stand alone rig. I also use a BFG rackminus and a WTF made MOLLE laser cut chest rig. The way I set my gear up I base everything on the belt rig, then add from there. I have belts with Esstac Kywi ammo pouches and BFG ten speed pouches. I like both for different reasons. If you plan on using this belt for multiple things a system like the Safariland ELS lets you configure your pouches quickly and easily. An inner/outer belt like the Esstac shooters and tech locks with the ELS clips means you can go from 4 pistol mags to 4 rifle mags to 4 shotgun caddies or any variant of those.