RE: isonic 105 - 111 - 115 ?
If you have a solid 12 kts minimum and are reasonable with getting a board planing in light wind (active early planing style) then you will be OK with the iS105 - and this board will be faster and easier for your weight at the higher (5.7m ) end of the range. If the wind is gusty/thin/patchy (inland lakes ?) in your range/location, and/or you are not often in 20kts/5.7m conditions, then consider the iS111 or iS115.
With the lighter Wood costruction, you'll have a better ride and earlier planing ; it's worth taking extra care on thebeach not to slam your board down into the sand, or stand on it on the beach with rocks in the sand - on any brand/construction. In lighter constructions (better on water) there will always be more chance to get some damage, but most likley will be when banged or pressured very hard onto something very sharp - just a little less care will make a big difference to the outcome. It's very rare to have a wood board " get holes in the hull just for being layed on an occasional stone in the sand..."
Slam it down on sharp rocks with a wind gust in the sail - or jump onto the board on rocks to check boom height etc will do it.. On any brand.
Cheers ~ Ian