Since they are limited to 5 per game, as mentioned, I'd think up a 5man squad, and double it. One squad would have the heavy weapon, one squad would have the special weapon, as no member can go out more than twice in a row.
I'd go:
1. Heavy Stubber /// Grenade Launcher (Gets Frag, Krak, Choke, Flash)
2. Bolt Pistol and Supp.Shield (Guard/cover the heavy/specialist)
3. Shotgunner (Seeker rounds are brilliant)
4. Shotgunner /// Handler with Shotgun and Cybermastiff
5. Boltgunner
The /// representing differences in the two squads. I wouldn't take power mauls personally, as you can either have Boltpistol/Powermaul, lacking some range and a shield, or Powermaul/Shield, completely lacking range, except for your flashbangs. Plus powermauls are devastating in-game, but everyone taken out by it is automatically A-OK after the game.
This is definitely a more 'shooty' version, and just one of many variants. There really isn't an optimum, as it's very much determined by who you fight, and what the board consists of.