I second (or third) the Kavil build with the Unhinged Astromech and Autoblaster Turret.
I typically play with two friends in 3 way battles and Kavil is by far my most reviled pilot because with the autoblaster and extra damage he's really effective at neutralizing their more agile ships.
I haven't used him since the new wave hit (I was on vacation and now I'm busy having fun with Bossk and Khiraxs) but he's a solid go to. I will grant that typically we play a 3 way 70 point game so it limits upgrades somewhat but really, that Kavil build is simple and effective. Add another upgrade or two and he's potent.
I'd probably pair him with some star vipers or khiraxs as the M3-As are a bit on the squishy side (but that would probably be less of an issue in 100 point games). Although if you're looking for pure swarm then the star vipers would be a bit expenseive but even just a base star viper can be fairly potent.