Brian, about a year ago I put a kit on someone's 2000. Part number used was 77211-99. That was the same part number I'd used on my last Road King also.
Both times (about a year ago and in 2002 on mine) that kit part number was already obsolete. Both times had the local dealership run that part number to find other dealers with old inventory. That last one, however, was really tough. Only one found was a kit that the dealer had already installed and couldn't make work. They'd cut on the harness trying to make it go. I got it going but it was a much larger pain than it should have been.
Still might try working with that part number though. Might get lucky. The kits also pop on eBay every once in awhile. The last option I can think of would be individual parts. Use that kit part number and get the parts counter to bring up its parts breakdown. Service parts for the units should still be available even though the packaged is not. You could order it part by part.