I picked up an uprated H4 wiring loom from the bay of parts last week - arrived couple of days ago.
Some very naughty sellers trying to sell the exact same item for over 5 times the price...
I paid £8 and the quality is very good, thick gauge branded wires with rating on side, good quality connections and the headlight connectors are ceramic.
The weak point I suppose could be the relay's but they are replaceable so you could swap them out for better quality branded ones if you wanted.
Not going to fit it just yet as it means removing a whole load of stuff again to get to the alternator wiring (which is the best place for the positive take off).
https://www.ebay.co.uk/itm/H4-H4-Headli ... 3101067003