Wiring loom for the entire engine-bay, or just the ECU & engine sensors & dash?
If you can get hold of the right type of wiring ("Tefzel" - there may be different grades - it's expensive but NOWHERE near as expensive as a roughly 500hp Redblock build) then it's not that hard to do the ECU/engine/dash looms yourself. Have to be YouTube videos on how to plait the wires before heat-shrinking, and the only "specialist" tools you really need are crimping/cutting (Haltech sells a good set) & heat-gun & a label-printer that uses non-heat-sensitive labels.
Haltech might even sell the starting-point for a loom? [My original MoTeC loom I got from MoTeC, was just the big ECU plug and much longer wires than you'd ever need wired into that plug, but I started from scratch with the replacement MoTeC a few years back with the more flexible Tefzel stuff]
The entire engine-bay &/or car loom is probably more complex ... need to have the OEM plugs, need to terminate the high-current cables correctly, etc.
