by and by SupTheCreek will be by with his thoughts ... all positive re the alana.

Sarah I bought a (second) Nalu 10 6 GT for my wife.

It weighs in at 10.9kgs, which makes it easier to load and carry than the GS version, which is what the Alana is. The extra kg or so weight saving is surprisingly significant.

Unless you're really in love with the graphics of the Alana, I'd go for the GT version of the Nalu.

You also get a thruster setup for the fins, which is probably better for your surfing

Supnube
Interesting question. I sold my last Mana last May so I never had them for a head to head, but you can't really compare them head to head anyway.
First off, I really like both boards.
Strangely enough, my 10'6 Alana weighs a full kg less than my 9'6 Mana (Mana was heavy when delivered at 12.9 kg)

The Alana is a longboard and surfs like one.... a very capable one. My favorite longboard SUP.... so far
I ride it a lot. In small waves it is great, but I am really having fun on it his winter in some well overhead, solid surf.
I am always amazed at how well it surfs. You can lay it down really hard on bigger waves in full confidence, pretty cool for a big board
The 10'6 noserides pretty well, but is not a "tip"rider for me.
It is just "ok" in the stability department for a 105 k guy, the Mana is much more stable.

The Mana can be surfed more towards "shortboard" maneuvers, with snappier turns and quicker off the top. If it weighed 8 kg, it would be a 1 board quiver for a lot of people.... the excess weight keeps it in the "really good" category in that size/market range.
I was very happy surfing all conditions on it. I had the 2013 version and loved it in small waves, but did not like it over 4'. The 2014 Mana goes great in bigger surf.
I actually prefer the Mana in flat-water, over the Alana, because of the extra stability since I take a lot of pictures when paddling.
The only reason I sold the Mana, was because I got my 9'6 Prowave, it did everything better on a whole other level and was plenty stable for all conditions, so no need for both. I was sad to see the Mana go, but I did replace it with the 10'6 Alana to add more variety in the quiver.

If I could only have either the Alana or the Mana... which would I choose?
that's easy, the Alana... no, the Mana.... wait, I ummmmm

I honestly can't say which one.... they both are very good in their niche', so it depends what style of riding you are looking for.

I'm including a pic of the waves I have ridden with the 10'6 Alana, because I am always stoked by how capable that board is.

1st = handles size and juice

2nd.... you can really lay into a turn with confidence... I have had a lot of short SUPs that didn't hold a turn as well. I run a single BIG 10.5" fin

TTM.... I have owned or used a number of Mana's and Alana's

1 Alana was light, the first one I tried
Ran out an bought one the next day, I looked at all the 10'6 Nalu's and Alana's.
Some of the Nalus were nose heavy to the handle, the Alana I chose was lighter, and well balance, but noticably heavier than the one I demo'd.

My Mana's were fine till one delamed and I was sent a replacement.... unfortunately it was a tanker.... 2 kg heavier than the one it replaced.

I figure that's where the +-6% comes in. Cept mine was +10%

My last 2 Naish's were heavy.... hopefully means stronger

10 6 Nalu is too much board for your weight/ size......you would have more fun on a smaller board for waves...

For your weight......the board's specs below is a better match I reckon.

http://star-board-sup.com/2015/products/converse-9x30/

if if you are too light you will have a harder job turning a board like a 10 6 Nalu....so you need something smaller, lighter etc but wide enough to be stable and give you some progression. Just my opinion