Options to the build.
1. You can switch around enemy armor damage and elite damage from the stats on the gear and mods, to the talents on the guns instead. You would need to change one main stat to Firearms and and one to Stamina on your gear (or change one and boost the other with mods), in order to achieve 3832 Firearms and Stamina stats for the minimum requirements for Destructive and Ferocious talents on your guns.
2. You can use two 260 electronic mods with 3% skill haste in order to max out skill haste to 50% (45% from the stats on gear).
3. You can use sticky bomb or support station instead of turret, depending on the situation.
4. Off hand weapon, up to you!
5. The purple mods with elite damage are sold by the vendors, 4% is rarely sold but 3% is up almost every week.