The KN8 is an Abit series, and the A8N is from Asus? ;-)
If you meant AN8 (the Abit series), the KN8 series appears to be newer. It
looks like the KN8 SLI does the SLI selection due to some added circuitry,
rather than requiring flipping around the small card like the AN8 series.
(My own mainboard is an A8N-SLI from Asus. It uses the SLI card, as does the
A8N-SLI Deluxe. The A8N-SLI Premium doesn't use the card, and it has a
heatpipe cooler on the chipset.)
Address scrambled. Replace nkbob with bobkn.