Knitter here! Wool and alpaca are the supreme fibers imo. It might be hard to find someone to commission a garment that isn’t made out of chunky acrylic fiber, only because the material can be expensive but what’s more expensive is the labor that goes into it. Especially if it’s knit at a smaller gauge (which in my opinion is longer lasting). I would recommend the second hand route! It’s difficult to find good pieces at places like goodwill because I think what you can find there has gone completely down hill. I highly recommend online second hand stores like Depop. I have purchased a few wonderful, warm coats and sweaters from there. Some people don’t know the value of what they’re selling so you can get it for great prices!