Here are some outside links that tie into the Chairs episode.
Just punch in your height and this diagram gives you the proper distances to adjust your chair. [Lifehacker]
Very nice step by step list to properly setup your chair and workspace. [Lifehacker]
This $230-$300 is an Aeron knock-off that gets a good review from Kevin Kelly.
Quite a cool accordion chair design that can be setup in many shapes and seat up to sixteen people.
If you have the time, this is a thorough slide show presentation that covers all the correct workspace distances and explains why. [Lifehacker]