Speedway wiring harness
http://www.ebay.com/itm/Speedway-1999-2002-LS1-Engine-Wiring-Harness-Extended-/131480960104?hash=item1e9ce03c68&vxp=mtr
The big issue would be the quality of the connectors. If they start breaking after a year or less that would be a really expensive harness.
I usually make my own from (or use) a stock harness. You can get a deal on one that is damaged or cut from a wrecking yard (or Pick&Pull it)

