I purchased mine from a store called "Relax The Back"
do you have one in your area?
Being in it is amazing! You lie back, swing the keyboard and monitor to you....was much more comfortable to me than the Aeron
here is the link to their site, although i did not see it listed on the site, i would contact a store near you. The one in Los Angeles near me had one on display in their store
http://www.relaxtheback.com