who makes it? companies etc

Makes it or supplies it? You would need to be placing orders like Airbus to go straight to the mill.

Actual manufacturers are people like Dupont and Dow I guess.

If you want to buy it theres a company called (I think) East Coast Fibreglass supplies, they do a lot of mail order and you can buy carbon cloth from them

CFSnet sell it...

Try Carbonology.com