It would be easier if you kept everything in one thread...

It sounds like you are interested in long-distance riding, if you want to do centuries. Most companies produce "endurance" bikes that have a slightly longer wheelbase (distance between the wheels) for more stability - you don't want/need a very responsive "twitchy" bike if you are not racing - and a slightly higher saddle-handlebar drop, with about a 3" drop from the saddle, rather than up to 7" for a racing aero position.

The Nashbar bike has a very short wheelbase, especially for the smaller sizes. If you take something larger than a 48 cm bike (about 980 mm), I would expect a comfortable wheelbase to be about 990-1000 mm.

In general, the Nashbar bike has large changes in geometry in different sizes - you can see how the relative proportion of the top tube is shorter as the seat tube / bike size gets larger. The largest bike actually has a *shorter* top tube than seat tube(!)... and the smallest bike has a much longer top tube than someone that size would normally take. Also, they do not give the standover height, so you would need to calculate that yourself... trigonometry redux.

The intro price for most endurance bikes is still under $1000 for most manufacturers; prices did not change for about a decade while bikes got better, prices went up slightly for 2009, and the prediction is a larger increase in 2010. Bikes might seem expensive, but considering the lack of inflation and the better engineering, they really are quite a bargain.