I'm actually currently in the process of collecting items for my own iteration of the MetroCop.
Helmet, vest and belts are the only items I haven't sourced yet. If you want the perfect shade of green for the pants, have access to a Kohl's and don't mind a bit of labor/extra work for the stripe, you can use these.
For the 'coat' under the vest, I am using this
with modified sleeves.
And if you are needing replica weapons, look on Google for the best prices for either a spring-based airsoft H&K USP Match (dual tone or "tomb raider") or any airsoft MP7 if you prefer your MetroCop have the "SMG" instead of the pistol. StunStick might be a bit more difficult to find without making one or having it made for you. (I'm using hardware store materials to make mine.)
As for boots, gloves, accessories (magazine holder, holsters, etc.), I've been using Uniforms Warehouse (link for the coat above,) to source most of it. Gloves are a little tricky. There is a low-cost approximation at Uniforms Warehouse, but they aren't perfect. Used to be a pair that were a dead ringer here
, but the link appears dead and a search for the product on the site yields no return. As of the time of this post, my e-mail in with the question hasn't been returned, but I also only sent it an hour or so ago, so that's not a big deal. I can wait.
The vest is something I am mulling over right now. Essentially, if you go by the world of HL2, that vest is a bit of body armor. Real bullet proof vests do give the look you'd need, but they tend to be one or more of these: prohibitively expensive, restricted items or the purchase thereof getting you on a 3-letter-agency's list. Things I've debated: Tactical vest from sporting goods/airsoft/survival/military surplus supply stores, getting a bunch of coarser fabric of the right color and making my own, or cannibalizing a shirt I have of the right color and going with that.
If I can ask, what are you using for the back of the helmet? I know the front is just a modified Soviet PMG gas mask minus the filter, some darker material over the eye pieces and a bit of brush painting to get the worn look, but... the back part I haven't found and will probably be fiberglassing myself unless you know of a better option?