I've sent Ridlins a message, since we haven't heard a peep from him/her on GEARs for over a month, despite their posting in other threads. If they are dropping out, then I'll hand that spot over to you, and introduce your character and Slyp's at the same time. 

Regarding the armament, yeah - if you wouldn't mind dropping the railguns to something like saboted cannon of some kind - they'd have to be significantly smaller caliber than tank guns, as GEARs are too small and light to handle the recoil from 100+mm cannon. But you could go for something like an Electrothermal propellant cannon to get an increased speed, or rocket-assisted projectiles or something at around 60-70mm or so? That'll give more than enough whack for anti-GEAR ops.