Try polevolt.co.uk
Failing that I can supply everything(including a loom) built by a pro, this can be in the BRAID to which you are reffering, or the better abrasion resistant heat shrink, as I have.
NB decent aftermarket looms normally use either 44 or 52 wire, these are aircraft grade wire, and it is roughly TEN times the price per metre of std wire.
I also have all the markers to go on the cables, can do one offs, can even have one fitted on your car as a one off no problem.
All/any mods catered for as well.
tabetha