In starplaza there are the shops Stardoll Boys, Fudge Boys and Fallen Angel Boys but there is nothing there for Rio. However if you go to search and search Rio Chicos you will find 6 pages of boy's clothes.
I thought this would be helpful for the boys on stardoll who don't have a wide range of clothes to choose from :) Thanks to an anonymous comment for letting me know about this hidden store!
.emma.x.