My guess is that they'll all arrive at shabondy in reverse order, so Brook will be first and luffy last. Some new idea's on how they might return:
Brook: Since they're all expected to have powered up, brook might now be able to run a lot further on the water, maybe even from island to island.
Sanji will get a ride from Iva after he returns to newkamma
Franky might even be able to fly, using some sort of space age jetpack.
I agree with the other one's mentioned earlier, only for Zoro I can't think of anything satisfying, maybe that unknown person on the island will help him somehow.