Befor the damage type rework, this build used Corrosive. it is still fine, but now, Viral should be better in most case.
Fire could also be a good choice ; Gas may be good.

Toxin is the best to one-shot Corpus, because it bypass their energy shield.

I use the loader Killstream instead of Splat, to start to recharge faster. with Pax charge, the recharge will stat just by going from a pack of ennemis to an other.
(it is slightly better, but if you have Splat, it is fine)