I understand you, but I guess what kilemall intends to say (I cannot talk for him) is that, if you're intending to use a 1:1 scale for the troopers, why not to use your standard RPG combat system (whatever it is)?
Most skirmish systems we have been suggesting to you are for unit combat, not individual one.
Anyway, if that's what you intend, I'd suggest you to look at
AHL
system, if you can get Access to it (I guess it's on FFE disks, but I'm not sure at which one). It's relativeely quick and with it you can represent firefights among groups of 30-40 people per side (some scenarios are close to it), and, while initially thought for short distance combat (inside an Imperial Cruiser), the ranges given for weapons allow for exterior combat too...
The only thing you'd need to adapt it is to adapt weaponry and armos, but I guess this would be easy (most laser rifles would be Laser Rifle or Carabine, Gauss weapons already exist, as most chemical propelled round weapons, etc...).