I am 5'11 / 139 lbs
boy, you skinny!
also, consider the carbonium topsheet when making your decision. If that's something you'd like, know that the SL doesn't have it
If you want some more info on the heritage/cobra, read snowolf's review thread of the cobra. He's ridden the heritage for quite some time so he makes comparisons between the two often in his posts on that thread