I think it's dumb, and tau. Dumb Tau...
In all seriousness, i think the firewarriors need a devilfish. At that points level, the extra firepower is huge. and them getting that one round of 15" fire is key, and can put a massive dent in the enemy army. I dunno what i'd take out, but i'd find a way to get them in a fish. cheap as possible. that way you can send 33 BS 5 S 5 shots into something at least once a game
You could also go with carbines. I know they'd only get storm of fire within 9", but that's still do able with a 'fish. And it would let you utilize unorthidoxy, giving you charge options, and pinning weapons that have a greater effective two shot range, but less effective overall range. something to consider.