Robes are a pain in the ass to make in DAZ, i'm working on totally not jedi robes a fair bit lately and the answer is pretty much dForce or go home if you're just using DAZ. The only other option is to use a lot of extra bones in the clothing but who wants to pose a model then spend an hour tweaking bone positions so a robe sort of fits.
Theres a cultist robe in one of sickleyields packs I think, the watchers of yadayada... the cthulhu-esque pack she did.