I've basically done what you're talking about but I have ain inspo/vision instead. The holes on my plate lines up perfectly with the holes on the case.
I used the counterlung buckles sold at golem to clip the counter lungs down.
DeepSeaSupply Counterlung Attachement Hardware
I also use their integrated weight packs, which are great.
Golem Gear, Inc. - Golem Gear Integrated Weight System for Backplate
I don't know that my selup is all that more streamlines than the stock one, but it works for me.