http://pikminlink.com/ . I had the pleasure of meeting her a few years back at Animethon13 (an Edmonton Alberta, anime convention)
She makes all her costumes and props, but does not sell them.
She does have an Esty store now where she sells hand made Elven crafts she is currently a game design student. She is probably the closest thing to a professional cosplayer there is. She is just ambiguous in the face enough that she can cosplay both male and female characters and really appear to be that gender or character. Her father is a professional photographer and both she and her father are regularly invited to Anime conventions as special guests.
She also has a really nice (in my opinion) layout for her website, with links to her blog and Esty store.
The Prop Lady
http://proplady.livejournal.com/ She really does make beautiful costumes and props. I've learned a lot of techniques from her tutorials.
http://www.katiebair.com/wigs.html and http://www.katiebair.com/zoocandy/items.h
http://stores.ebay.ca/COSPLAY-WIG is an ebay store from Hong Kong who I deal with just about everytime I need a wig for a costume. They sell the most fantastic quality wigs and have them in many stock styles as well as many that are styled and coloured to the current most popular Cartoon and Video game characters. They will even reproduce for no extra cost a wig they formally had on their site but do not carry anymore if you have the picture of it.
And of course the many inspiring individuals who post on Cosplaylab and Cosplay.com
features contests and resources for cosplayers
Taken from the website
Cosplay Lab features tens of thousands of anime, manga, video game, J-Rock, sci-fi and fantasy costumes created by people just like you from all over the world. If you're new to cosplay, or are a seasoned cosplayer, Cosplay Lab is your one-stop shop for maintaining your entire costume collection, organize cosplay skits and photoshoots, meet other cosplayers, get info on upcoming anime conventions, and way more!
Cosplay.com is an online hosting site for cosplayers photos, sales and tutorials. They also have many links to supply stores and lists of all the various conventions.