I would recomend the 9'5" Mana over the 10' Mana and although it's not quite as stable it surfs so much better and is noticably lighter to carry.
I'm your weight.. I live in Melbourne.. Where are you because you are welcome to paddle my 9'5" Mana before you buy one to help you make up your mind.
This is a vid that I did a while ago that shows how good the 9'5" Mana is.. It's an awesome board.