Oh, Wilson's gone. Sweet.
I've recently garnered some inspiration for a new nation concept. If I don't suddenly vanish again, I'm going to post a WIP within the next day or two.
Additionally, if you seriously think that modern firearms are somehow incapable of contending with the body armor in this RP, then you might want to revisit contemporary firearm technology (specifically the plethora of cartridge phenotypes that a firearm can be chambered for). For example, your standard FMJ round is not going to have the same penetration values of an APDS cartridge or a round with a tungsten (or depleted uranium) head. If stopping power and penetration are both still an issue, move on to the next little-known stage of firearm engineering: gyrojets, electrothermal-chemical technology and improved propellants (such as bulk-loaded liquid propellants or nano-engineered solid propellants).
There's more to infantry weapons than just lasers, railguns, and plasma weapons. To be honest, a modern high-powered anti-material rifle that's chambered for the Russian 14.5×114mm HMG round is capable of destroying light-armored vehicles with relative impunity. Give one to a soldier that's wearing a bog-standard powered exoskeleton, shove a smart sight on it and boon the Russian HMG round with the capacity to correct itself mid-flight (yes, self-guiding bullets do exist:
http://www.iflscience.com/technology/darpa-has-created-self-guided-mid-flight-changing-bullets) and you now have a soldier that has nullified the anti-material rifle's greatest weakness: lack of mobility due to the weapon's innate mass.
EDIT: Of course, the above ignores logistics, the nature of urban combat and the training needed to operate such a hefty rifle, but meh.
EDIT 2: Although the RP has a single nation that utilizes particle accelerator weapons that can fling antiparticles at FTL velocities. Which can somehow only be guarded against by employing energy shields or [nanogibberish] armor forged from [nanogibberish] wonder materials.
>Powerscaling
>Duck actually reading appsPick one.