I've been looking for a while. Most companies I have spoken to just offer a stock loom - which is no good if you want to customise it to add toggle switches, spot light, heated screen etc.
The ones that say they can customise it for you are either very expensive or just don't bother replying back to you.
So, I have decided just to make my own too and ask the wiring technicians at work to supervise.
Very surprising though - looks like an area of the market that is a bit empty and a good opportunity for someone who will listen and advise their customers :roll: