Overkill would... well, okay, it might be if yeh just slapped all the non-detrimental flags onnit and ramped all the stats up to th'max. It's only overkill if you crash th'game with integer overflow. Everything else is merely sufficient... and perhaps a wee bit unbalanced.
Still, in the meantime, speed 10 (reload, now? I forget...) would do. It doesn't (have to) stop firing until it runs out of ammo/energy ^^. Speed 10 BV 10 energy weapon in GH1 was a hoot, even at DC1. Dakka everywhere.