Gothitelle is the far superior locker IMO. Why? Because it is a LOT easier to get out. Since it doesn't lock your items, you can use rare candy on it. If you do that with vileplume you'll have all of the rest of the rare candies as dead draw. More importantly, however, Gothim has 60 HP while Oddish only has 40. That means Yanmega can't eat it without the aid of a catcher. Its still not ideal since you can't drop it out of nowhere like in D/P-PL, but Gothitelle is so much easier to get out than vileplume its not even funny.
As for energy, Psychic has the option of jirachi + mismagius for energy accel.