Do a google search or ask at a local clothing store. I am sure there are micro fabrics and fillers that would benefit you. Good luck.

Fleece jacket are good as lightweight

I agree that down is the lightest possible coat to keep you warm. There are some new types of fabric coming out that are light and keep you warm. If possible, you could use long underwear (I do) and wear a lighter coat. Also fleece seems to be very warm.

I’m searching for a heated jacket. Most seem to be for trades people and motor bike riders

Yes I have the same problem with anything warm seems to be heavy