Those are good but assume you already have a bike. Here's a related article along the lines I was thinking. It's a bit light, and could use more content, but a good reference point, I think:
http://www.doctordanger.com/motorbikeroad/buy_roadbike.htm
And a less related but FAR more comprehensive article (11 parts!) mostly related to racing but that could be of interest to people interested in the entire process of getting a race license, prepping a bike, protective gear, etc. I think a lot of the advice could be transferable to track day riders. Takes until Part 5 to get to race bike mods, but still a good read to see what some people do, or what the previous owner may have gone through (scroll to the bottom of the page for links to the other sections)
http://www.motorcycle.com/how-to/road-racing-series-part-5-88283.html