When I worked for Metro - I was able to get approved an external carrier. We used the Pointblank R20 carrier. Its the basic carrier with pouches and a pouch dedicated for comms. It served its purpose but due to the light blue color I had, it didn't hold it's clean look without much maintenance.
I know the officers in Clark County Nevada are using the same carrier but in black and I am sure (other than dust) it's a bit easier to keep clean.
I was able to secure agency pricing for the R20 carrier at one of the local cop shops - so it only cost us $104.00 with the regular price being $140.00
I moved agency have been approved for an external carrier but in the style of our uniform. I suspect I will be getting the Blauer armor skin in grey.
If I could buy and wear an external carrier with pouches - I would make sure to buy one with molle on the bottom half so that I could attach designated pouches that work for the gear I want on the vest and not generic pouches like on the R-20 carrier.
Essentially a cross between the Blauer (uniform on top) and molle on the bottom for attachment of pouches would be perfect. You can have them made by companies like Turtle Tracks whom makes a majority of Alaska State Troopers vest, etc.
They would be more pricy but well worth the price in my opinion. You just have to research the type of vest you want and make concessions for price.
If you utilize the search function here - you will find plenty of other threads discussing external vests in the Tools of the Trade area..