If you want to be super high speed, take a look at these PC's.
Ferro Concepts FCPC (I use a v4 but the v5 is much more updated with a lot more features although you'll have to pay quite a bit for components)
Crye JPC 2.0 (the standard go-to for SOF)
Perroz Designs LPSPC (Toronto based gear maker that gets government contracts for his plate carriers)
Spiritus Systems (some people like them, I personally don't as much due to the cummerbund attachment method)
Mayflower/Velocity Scarab (as a base carrier, it's very well designed and thought out, however you'll have to spend quite a bit to get it fully decked out and truly functional)