Hi FirieJase,
It's always best to demo ride a board if at all possible. It's not about the size, there are so many other things to contemplate also. The 131 should be OK. I ride an Airush 2008 132 X-Pact most of the time and I'm ~87kilos. It's good most of the time, except in very rough chop when the shortness of the board is more apparent.
Boards are a very personal choice. Most people love the Protoy, but it's not for me. It's best to find out what works for you!
Good luck,