Richarda,
Welcome to the forum.
As Woody Girl says, sweaters are knit, not woven, and their function is to trap warm air, which is done with a loose structure. Tightly woven wool, as used in whipcord trousers, can be sewn into a garments, but isn't going to hang the way a sweater would. Maybe make a shirt, like Swandri or Filson. Strange to ask for sources on a UK forum when you are in Canada and usually have much better access to fabrics than we do in the UK.
I have merino wool knit "sweaters" by Aclima that are certainly not low quality, some have been worn almost daily for years. There are other makes of quality wool insulation layers, and if you are willing to import the fabric, I would recommend looking at just importing a finished sweater.
Unless you know what you are doing, buying fabric (expensive and hard to source fabric) and hoping to make a better/cheaper garment than you can buy from somewhere is usually optimistic and unlikely to be cost effective. My mum knows how to sew clothes, and I asked her to re-purpose a Swandri Mossgiel into a jacket and wished I had not. She had a
really hard time, and she had been making clothes, including wool re-enactment dresses, for over 40 years.
A little more info about you and what you want this garment to do would help
Chris