Good cable boards i would recommend is a liquid forse FLX amazing board on kickers and rails. I have heard alot of good things about slingshot boards on cable as well, i actually just ordered a slingshot board recently and cant wait to ride.
yes i honestly think thats way to big. Do you have bad knees. if you want a board with more surface area go for a 139 maybe 140 but all in all a 136 or 137 would be perfect size for you. some boards that go up in size just get more bulky. Some boards like slingshot you might be able to go a little bigger since most are featureless and very light.
I'm 5 foot 10, 165lbs and just got a Liquid Force Super Trip 139. Yet to ride it due to injury, but did a ton of research and the overall consensus was that the board would be a perfect fit for cable riding at my weight/height.