fivewits wigs is an in US wig store and they do have character wigs. Cosplay fu is outside the US(I think) but I've heard good things! CosplayWigsUSA also is a wig company here in the US, and they have a good amount of character wigs.
That's about all I can think of!
Next Convention: Anime Detour
Daenerys Targaryen- Game of Thrones
Blackfire- Teen Titans
Tharja- Fire Emblem: Awakening
Opal Beifong- Legend of Korra