Ok - comparing the two boards you have listed.

IMO - the 11.6 Nalu is a fantastic board that paddles nice, surfs very well and is one of the funnest boards you will ever own.
IMO - the 10 Mana is a slow and frustrating paddler, surfs slow and doughy and is one of the least funnest boards you will ever own.
I will bet that people are going to tell you that both boards are way too big for you, and to some degree, yes they are, but don't be swayed too much by that because I owned and loved an 11.6 nalu and I was about 75kg - so stick to your guns and buy the 11.6 - its a big sic board.

Mooty,
Go the 11'6 Nalu. I also live up here in NQ and have used both boards. The Mana is no fun on the mushy stuff we get up here. I found it frustrating to paddle as I could only take 2-3 strokes each side before the board would start to turn. The Nalu will be super fun and you will be able to surf it. I found it easier to paddle which will help in catching the small waves up our way. It will also be better for balancing the kids on the front. Definitely not too big for NQ conditions.

I think the 10' Mana.. unless you want to paddle with kids on the board with you and then the 11'6" is the better board for doing that.. I think the 10' Mana surfs great and much better than the Nalu and I love paddling mine on flat water.. I don't have any problem with tracking or yawing.. I have a few friends with the 10' Mana's as their only board and mostly paddle flat water.. and love it.. The Big Nalu is a big heavy board for your wife to carry and Mana is much easier.. The Mana is very stable and a great first board IMO.. If you want to paddle distance or do down-winders the 11'6" is a much better board for that.. You might also want to concider the 12' Glide.. It's a much better board for flat water and down-winders but not as good as the others in the waves.

Demo first if you can.

DJ

12 glide

I will do all the stuff you are wanting to do better than the other two. then the 11'6 then go the 10 mana. My wife who is about the same size(55kg) loves our 12 gide but gets frustrated with the mana because she is to light. If she stands forward the fins only half stick in the water and if she stands back the nose rises and catches wind. Too much rocker.

the mana is a great board for a bloke 90kg + who will surf 1 to 2 foot waves

IMHO

I ended up buying a 10'6 Nalu for the 58kg wife and a 12'0 starboard for myself (big size disparity between her and me, not easily bridged by one board)

Wound up going with the 11'6" Nalu. We had a good fun session on the water this afternoon and see that this sport can be very addictive and also family-friendly with kids sitting on the front of the board.

Thanks, DJ. We just went with the AST board. The wood looks fantastic but couldn't justify the extra $300 for a board that will inevitably get banged up with kids climbing on and off the stick and us falling and slapping our paddle against the deck. Once I get a hang of the SUP, though, I would love a wooden deck and maybe that alternative will become reality when I look at my second stick.

We enjoyed a nice flat-water paddle this morning from our beach to the point, which I'm guessing is about 0.5km. My 8-year old was on his little foam paddle-board from the SLSC and my 6-year old was sitting on the nose of my board. This sport/activity is the way to go. SUP is going to take off big-time!

You're right, though, in saying it is a big board to handle for my wife. She can't load it onto our Hilux by herself. It is also taking up a lot of space in the garage that we'll need to sort out storage. I saw your shed. Unfortunately, we're not blessed with that but we do have a 2-car garage so will be looking at some sort of set up to hang the board(s) off the ceiling.