What brand is the 11'6" that you're currently paddling?

JR
The volume doesnt always mean stability for a larger person. I am 6ft4 and 110kg and I have trialled the 14 naish and the 14 Bark. The Naish being a larger volume board yet less stable. The reason is us larger persons sink the board more and the larger volume yet narrower board tends to sink more and act like a cork that is top heavy. Go and try out some 10'6 boards which are fish style, slightly wider at 29 to 30 inches but thinner.
The 30 fish style inch board displaces the extra weight and makes the board more user friendly for the surf environment. For the flat water trial trial trial. If your in Sydney dripping wet at Manly and east coast on the sth side have an array of boards to try.
cheers

You also need to keep in mind what you want to do with the board. Do you plan on surfing it or just flatwater or a bit of both ? If its surf/allround then fully agree with simondo - a good starting point would be to demo the starboard whopper and naish mana 9.5/10.0. I am only a relative lightweight and have paddled both the boards and they both have masses of float/volume and have awesome reputations for their surfing ability. If you only plan to flatwater paddle then you may need to start looking at boards over 11ft because they will offer much better glide although not necessarily any more stability.
Demo as many boards as you can and now is a good time to be shopping with so many new models arriving in the near future.
Good luck with it.

I had a Simon Anderson carrier.. at 10' x 32" it was so stable you could park your car on it.. But it was lot lower in volume than a few of the other brands (157L) so it went really good in the surf.. although i sold it i still think it was by far the best big board i had ridden..It would hold 120kgs no problem at all

Sweet looking board too