great looking boards ...151 .and if the same price ...carbon for sure .
i use to have a 150 litre as my light wind board ,due to the extra width in the new boards it has been replaced by
a 130 Titan @ 85 wide .Im 95 kgs .very early planer.with my 8.5 .12-15 knot needed with my weight.
but if you are looking to do very very light air the extra foam will help pop you on the plane ,
keep in mind if it hits 15-18 knots when your out there ,with your weight ,you wish you had a 130.
depends on what range of wind and size sails you have .if you got the 151 and you have a 8.5 with your weight ....you will plane in 11-13 knots I reckon.

Its sound like you are a pretty advanced sailor ,in your case i would go smaller ,you may get more use out of the board and not think of it as a big pig.