hey quick question for everyone, first off demoing these boards is not an option, alright so im ordering a 06 3ds soon and i need to know if i should get a 139 or 143, right now im 6'1' and weigh 150 so which board size should i get?
I agree...the 139 will be a great fit for you. You might think about getting some smaller fins and possibly replacing the "stock" a-wings with some p-wings. The board is really tight with the 1.1 a-wings that come with it. I think it is a great all around board and you'll be very happy with it.
I would not go to the 143 unless you think you will be packing on another 50-60 pounds in the next year or so. If you end up being 250, then yeah, get the 143...but if you use that argument you should be buying everything too big for yourself.
No reason to buy over your size when chances are you'll want another board in a couple of years anyway.
Use a string to measure it along the bottom of the board. you have to contour the shape of the board to get a proper length, take into account the rocker of the board. tip to tail with a tape measure in a straight line will never be accurate.