Based on the your size, I'd go the medium. I have just bought mine, and I am 5'11" and ~ 170 lbs.
Here's a good article discussing the size options
The key quote from the article is "I would guess the max paddler weight should be 145."
Try sitting one if you can, and see if you get your feet with booties to fit.
Hope that helps. You could also talk to Jackson via their website.