For board shops in Rio the best place to go is Macumba, there you have a couple of surf shops that have the cheapest deals around. They will certainly put the Zona Sul shops to shame, but it is very difficult to find them and if you don’t speak a little Portuguese then it’s even hard to buy from them. You can find the addresses on this site: Board Shapers in Brazil that has many of them listed.
Board Shops in Rio – Galeria River
Located in Arpoador, Rua Francisco Otaviano 67 map this small mall has around 6 surf shops. Good place to talk to the locals, they speak English, and get your wax/leashes/fins etc. Prices here are a little more than what you would expect, but hey look at the location. There are a couple of places in the city centre to get your stuff, but the difficulty of it makes it not worthwile.
This you can either do in some hostels, sometimes they also rent out in that Galeria River in Arpoador. On the beach in Barra de Tijuca they always rent out (close to Quiosque do Pepe is a safe bet). Around the state just keep your eyes open or ask around.
Agave Wooden Surfboards
Thomas Scott makes wooden surfboards from agave in his backyard here in Rio. Check out an article about him by clicking this link. You can contact him by either e-mailing tscottsurfboards|at|gmail.com or phoning (21) 9568-7024.
If you want to buy board shorts and other surf clothing you can go to the Galeria River mentioned above, there you find brands at a pretty high price level. The same is the case with the stores along Rua Visconde de Pirajá in Ipanema and the shops in the big mall Rio Sul in Botafogo. A cheaper alternative is the stores of C & A, one of them you have on Av. N. Sra. De Copacabana 749 in Copacabana map.