I have Henry Miller Aeron chair. It's mesh back and seat to keep your tush cool while sitting for hours. They're not cheap but checkout craigslist, a good price is below $300 used. An after market headrest is available on ebay. http://store.hermanmiller.com/Produ...haNCGdOhkGXzYJdOA_HGmS4Vh8545AgL1bBoCtZ7w_wcB
I've kind of bought alot of different computer/desk Chairs in the past... Sometimes, Simple is best.-- I currently use just a basic green steel chair: I find expensive, fancy, plush, ergonomic chairs and what not...to be rather distracting. -- and kind of annoying.
They come in 3 different sizes, C being the large. I'm about 187lbs, size C and it fits me fine. What's nice about the Aeron purchase used, You can always resell for your purchase price. They hold their value around 300 +-50.
My old office chair was similar to this one. Had heaps of width and really high back that was high enough to rest head on the same flat plain as my back. (I'm not sure if this is the exact but check measurements if its something that might suit you.) Only issue I had was the padding was slightly to thin and over time (years) it compressed. http://www.ebay.com/itm/Boss-Button...858940?hash=item3d2754923c:g:EkgAAOSwCGVX7-OC Current one is very similar to this one. Has heaps of padding and is comfortable for long periods. Its not as wide but still wide enough. Mine also has a locking pin to lock the chair to stop it being able to tilt backwards (recline). http://www.ebay.com.au/itm/Reclining-Genuine-Leather-Office-Executive-Computer-Chair-with-Armrest-and-Wheel-/310851828199?hash=item48603679e7:g:UXsAAOSwCGVYBuxS Do a search on your local ebay for "leather office chairs" (High backed). Then search google for other sellers in your local country. There are some good buys around if you spend a little time checking and comparing. You will want to take a little time to learn the difference between PU leather, bonded leather and other types of leather. Just so you know going in what you are actually paying for. A lot of sellers like to hide or change terminology for lower quality products. These can still be OK depending on what your after. http://www.leathernet.com/leather.htm Make sure to check weight limits for any chairs you are looking at buying! They do differ. The usual issue will be the actual base weight rating and you can buy after market replacement bases that have really high weight limits. You can also get replacement gas struts in a range of sizes if you need it higher or shorter for your particular application. Leather isn't the only way to go, there are plenty of other good covering around but a GOOD leather will last if its cared for. Your other option is to check Gumtree if your in a built up area or auctions of office equipment. If your sitting at screens for long periods trading, comfort is important. So good think/plush padding is really a point you should focus on. Its a luxury that pays for itself over the long term.