when i done the loom for my ZT 3dr i bought one of ryans looms and cut and shut it suit, wasnt too hard really.

if i was doing it again tho i would use longer wires and try and run them throught the chassis rails etc where possible to keep as much wiring as possible hidden away to give a cleaner engine bay look.

but if you have the tools to do it, its really not that hard. obv overbraid looks better than tape, and use the propper rubber boots on the connectors etc to look good, also ident markers etc.