@ OP I would think a 155 size is decent for you. I would get a wide if I were you but its all up to you. I don't know what to say about what type of board you should get. But click the link below.
@ Poster bellow, if you are new I don't recommend you get that bored. You should watch some reviews on it, I watched several reviews and majority of them class the board as a intermediate to advanced board. They say if you go all out on a board and you're new you won't even recognize the difference if you road a different board before. It may also make it harder for you with all the new technologies. Thats actually the board I am planning on getting, the k2 raygun.
Both of you should check out this link: Best Snowboards for Beginners | Made Manual