Here are the weapons I talked about earlier + a "sniper" SMG that I really like as well.
Solo playthrough with Mordecai.
This is the shotgun with the (IMO) insane fire rate. Does quite a bit of damage too, too bad the accuracy isn't to boast about (Previous version was also called "Spiked" and had 60 accuracy or so, but much less damage and fire rate.)
Here's the lightning variant, Maliwan this time though it's the same design as Vladof.
And the sniper SMG I found. Keep looking for Hyperion II SMGs I said to myself after finding a previous version which had as much accuracy, but less damage and fire rate. And so I have