Mothim can breed more Burmy and spit out the females that you need to get all three cloaks. I actually ended up with four, and that means I have the three evolved in their respective cloaks and a spare.
I could be talked into the spare. Whatcha offering? I should note I have all Pokémon in Black, so anything offered would likely go to White 2 if I like it for that game.
Combee IS hard to get. Don't have a female in White 2 yet either, and I have two Hidden Ability ones. It's also a breeding marathon, but I might be able to try (I do have a Vespiquen).