I want to cosplay as Daenerys one of these days too...
I do really like the detail of Cersei Lannister's gowns as well, but I don't think I'd specifically cosplay as her. I would just make the gowns to make the gowns.
I look terrible as a blonde and the only blonde character I've cosplayed as is Saber and I'm not even sure how i feel about that. I think for Dany, I'm going to go with a white wig and maybe mix in some blonde and silver fibers but not too much.