Recommend a good ergonomic chair/desk?

Can anyone recommend a good ergonomic desk &/or chair?

I am having neck and backpain, I believe related to my office chair and desk (as I have already replaced my matress and pillows with ergonomic ones).

The article below has some guidelines for selecting a an ergonomic chair:
http://www.spine-health.com/wellness/ergonomics/office-chair-choosing-right-ergonomic-office-chair