I read somewhere here before that JB was around 6' - 6'1" when he played Boba. This coresponds with all official character profiles I've read about Boba, which list him as being 183cm tall.
This sounds perfect for me since I'm 6'1" and a slim build but whenever I watch the movies Boba always seems really short to me. Maybe ist just me I guess but I always thought of boba as a short guy.