What size surfboard should i get?

Ok so im a bit of a kook. Last summer i started off with the typical wavestorm board. however, after a year of wavestormin, im pretty sure ive got the basics down and i really want to switch to a shortboard. my question is, what size should i get and just overall what kind of board should i get? where i live the waves rarely get bigger than 5-6ft which is good cause im a beginner. any help is appreciated. thanks