Drag Queen and King Help (More sites to be added)
Here are some sites for queens with clothing, jewelry, wigs, make-up, etc. (I also recommend shopping around thrift stores like Rockstar and rogers and learning to sew and create things yourself. Hyvee also has really great cheap make-up that is fabulous for Drag Queen use.)
The sites above also have some things to imitate breasts but here is the site that most queens get breast plates from. Be warned, they are expensive. Lowest price being $625 (in the us. $675 if out). But these are well worth it.
Here are some websites for Kings: