definitely demo the 10 & 9.5 mana.
I am 100kg 6'2" and borrowed a 11 NSP for 3 months to learn on ended up buying a 10 MANA 3 weeks ago after demoing boards, i would have liked the 9.5 it turned much easier but need more time on the water with my weight maybe next year.
but you can't go wrong with either. IMO the 10 MANA is more stable in the chop than the 11NSP with it's extra width.