Much as I'd rather not (one of the things I hate most about TW is how needlessly abstracted infantry are), I'm not entirely sure what else there is to talk about if we do. The way TechManual handles infantry weapons, you've got roughly three points of decision to min/max: speed, range, damage; pick two. Unlike on 'Mechs, there's not actually a reasonably balanced tradeoff between weapons, so it's relatively easy to identify the three breakpoints.
Speed and Damage: Highest damage primary weapons available
Speed and Range: Highest range primary weapons available
Range and Damage: Highest damage primary weapons; two of the highest range secondary weapons available. If you prioritize damage over range but still want both, pick whatever range 5 or so weapon has the highest damage.
It basically comes down to if you want fast(ish) platoons, don't use secondary weapons. If you don't care, use Clan Heavy Support Lasers.