I am currently in Driftveil City, working through Team Plasma at the Cold Storage.
What 6 should my party be?

-Blitzle (lvl 24)
-Servine (lvl 26)
-Sandile (lvl 26)
--Ducklett (lvl 25)
-Darumaka (lvl 27)
-Herdier (lvl 26)
-Roggenrola (lvl 10)
-Woobat (lvl 10)
-Audino (lvl 13)
-Patrat (lvl 12)
-Sawk (lvl 18)
-Tympole (lvl 15)
-Tumburr (lvl 17)
-Sewaddle (lvl 18)
-Scraggy (lvl 17)
-Purrloin (lvl 14)
-Cottonee (lvl 15)
-Gothita (lvl 19)
-Tranquill (lvl 24)
-Swadloon (lvl 21)
-Yamask (lvl 21)
-Fonngus (lvl 23)
-Liepard (lvl 22)
-Simipour (lvl 27)
-Deerling (lvl 22)
-Karrablase (lvl 22)
-Vanillite (lvl 24)
-Minccino (lvl 24)

Darumaka can probably get you through it alone. Just choose your other strongest pokemon for now.