Go over to www.evocommand.com in the Beyond the Call of Duty section. You will find all kinds of vehicles for proxy. Just look at any of dsfrank's topics.
As for troops I'll say it again. MP models measure up well with what is called true 25mm. Presently the only modern range of figures that match up with them are the Kriegspiel line by Eureka miniatures. All other ranges will be larger. The next in line most likely will be Mongrel Miniatures. They measure 26.5 on the barret scale.
I suggest Kriegspiel the line of minis are sweet. Plus over at the evo site we have been talking about making a poll to see what figures the community would like next. Presently there are a few gaps in the MP line since they put on hold future releases.
1. USMC weapons section. (AT weapons)
2. EFTF weapons section. (AT weapons)
3. USMC command (this can be handle with the US pack from Eureka)
4. Snipers for all PLA, MEA, USMC.
The Kreigspiel line has multiple poses in a pack, and the genaric enemies packs (4 of them) along with the Insurgents packs has enough different types of models to use for just about all 3rd world, Russian, PLA, and MEA needs.
The reason for the poll is that Eureka will make new figures if they get enough request thru thier 100 and 300 clubs. These figures really do match up well with MP. I know I ordered a boatload of them, and will have my government MEA up and painted in the near future.