Seen in an issue of 4WD Action a bloke done a SAS in a weekend on his 2000 IFS. He used a LN106 front diff to maintain the Hilux wheel track. Have a search around, I'm sure you'll be able to find that.
I'll edit when I finish work if i can find the exact issue to help a bit more.
Edit: this link may help
viewtopic.php?f=49&t=27103Edit 2: Tough 4WD Utes Vol 2, a bloke with a '94 solid axle Lux done a rear coil conversio
4WD Action No. 263, this is the issue i mentioned earlier. And to correct myself, his is a 2002.
Not sure where you'd be able to find the copies of these magazines, but it's a good starting point.
Hope this helped,
Cobba.