Do you guys think the alana 10'6" would be too big for me?

It would be good if my boyfriend could ride my board sometimes, he's 100kg and tall ( I don't know how tall). But I am less concerned about that. I'd rather get a board that performs well for me and find him his own.

The ten six is working well for my wife. She is 60 kgs. Such a stable board with a wide platform. She plans on doing some yoga on it when she is good enough.
Our young kids sit on the front of our boards at times.
Was told this board is great in waves also.

The 10'6 Alana (Nalu) would be fine for you in flat-water and in the surf, it would be good as a starter board and a keeper as you advance. They are a keeper.
And... your boyfriend will probably steal it from you

Mine weighed in at 12 kg, but my last 9'5 Mana weighed 12.88 kg, so it depends on the board....
In my experience, they vary a lot. If you have a chance, pick them all up and pick the lightest one

I would go with what STC ^^ above said. If you have to carry, load the board, factor that in. 9'6 ish, smaller being easier to handle getting to and from the water.