As far as I remember, on gondola station they offer for rent Rossignols or something like this, ordinary boards, ok for beginners. But Ulen ski school (official provider) that is also located on gondola station is not the best school to take lessons from - many people say that they didn't teach them anything.
Google method bansko and their page comes up, they aren't great at fast response but well worth getting in touch with also there is a guy called Lewis who has posted on this forum, he lives and teaches snowboarding in Bansko, look up old posts from him.