Here is the beautiful Bertoia chair that runs $539.00, plus $150 for a cushion. I'm pretty sure you're going to need the cushion, that is of course unless you like playing checkers on your backside. (I guess I'm assuming you will wear pants and that should help a little.) If you would like to buy this lovely and a few of it's friends check out All Modern. Just make sure you wipe the slob off your face before you leave the computer.
Here is the nice alternative from IKEA that retailed for $49.99. The Solvar chair has a similar shape but obviously the materials are completely different, but still will give a nice look with a low back. I also love the white legs! Oh Internet Gods, please let an Ebayer or Craiglister be kind and gift us their unwanted chairs.
Check out this paint job that was featured in Martha that someone did on the Solvar chairs! Awesome!