What kind of snowboard should i get? and what size?

I am 5' 10 and weigh about 120. Im lookin for an all around board i can cruise on and use in the park. I live in the east coast, and the mountains i would regularly go to dont get much powder and can sometimes get a little icy. I've been renting a board for the past couple years but am looking to go more frequently. Any Idea on what size I should get? and specific models? I've been looking at the k2 anagram because it sounds good and is pretty cheap, but everyone makes it seem like an entry level board. Is it a board i can use for a while or is it for people who are learning to ride.