if lecie windows was an option on your model then the wiring should already be in place - holden (bless their cotton socks) take the cheap way out and fit a standard loom for each level and add / subtract options as req -my vs acclaim has all the wiring in place behind console / stereo facia and in the fuse panel -all i have to do (when the wife releases the funds to purchase) is buy switches relays and window regulators
suggest you purchase a gregoreys manual - mine have paid for its self 10 time over- and have a look at the wiring diagrams for color codes