Panther and orion, killshot as well maybe. U don't need sentinal, u can get it for tier progress but nothing else. Use aegis if u have it tho. Get storms 10, grav 10, and any others u may want. Dupe both of those weapons. Rank orion twice to rank 6 and put dual storm 10s on him. That'll to ridiculous amounts of dmg. Panther and grass are good enough but not in 2v2.

Definatly get storms. They are arguably the best in the game. Dual copy the 10s and rank up panther, and not many will stand in your way

Storm racks and priority for orion. 

Storm racks definitely! In the future you will unlock lacewing and lacewing is overpowered with storm racks.