I have one of my pouches from CTOMS. You might like what they have.
I use a frontline with shingle (3 M4 mags).
http://www.ctoms.ca/t/equipment/ctoms-signature-series
[url]http://www.ctoms.ca/home[/url
I also have used the BDS medical harness/vest in the past and it worked out pretty well for me, problem for me it was not modular, so you can not tweek it for your needs, but overall it worked well with a plate carrier.