To each his own, I guess. With the raceday wheelset, my SID-equipped XC race bike is in the low 20-pound area sans accessories. Prior to that, I had a 22-pound Stumpjumper with a Fox F90 RL, which was also good, but I really wanted a bar-mounted lockout for racing. It might be worth mentioning that modern SIDs (1) have bigger stanchions than the old noodly ones did, and (2) come with through-axle options in the longer-travel flavors. Mine's a SID XX 100mm, short-stroked to 80mm, classic 9mm axle, and seems adequate for fast XC.
Regarding "twitchy," if I remember correctly, that Kona has a pretty slack head-tube angle already, 68° isn't it? Versus 71° on my Stumpjumper, for example.
It depends strongly on what you pick. PricePoint has a
sub-200-gram saddle for $40, which might be a good 0.3-0.4 pounds less than your WTB. For myself, the first place I'd go to save weight would be the tires, and the tubes if you're using tubes, but then again not everyone likes light "raceday" tires like the Continental RaceKing 2.2 Supersonic.
Anyway, you might want to just pick up a cheap digital scale from eBay, weigh your bike's parts, and heave the weights into a spreadsheet, then mess around with alternate configurations and see what gets you good bang for the buck. Here are a couple sites you can use to find real-world weights:
http://www.velovert.com/matos
http://www.veloptimal.com/index.php?menu=photos_poids
http://www.fotos.light-bikes.de/main.php?g2_itemId=199
http://www.sicklines.com/weights/