I currently use an Antec NSK3480 for my LAN party rig with a Core 2 Duo and GTX 285. Cooling was not a problem whatsoever. The biggest problem was getting enough power, as you can't really use a PSU that is longer than around 5.5" or you won't be able to use an optical drive. The best bets for PSU are the now discontinued Antec TruePower Trio 550W/650W and the Rosewill 630W that was a Shellshocker at Newegg this morning.
I have an X-Qpack2 that I used to use which will fit just about anything, except you will lose the use of the lower 5¼" drive and you will have to cut that bay a bit to allow the PCIe power cables through. See the HardForum link that Massive Overkill provided.
The Aspire X-Qboii and Cooler Master Centurion 541 are the same chassis internally. I've done a build in the Cooler Master and it worked just fine with a 750W PSU and a 9800 GTX (10.5" long card). I did have to remove the FDD bays to fit the video card, but the dual HDD bays are intact.
I've also done a build using the Silverstone TJ08. It is made by YCC and is the same chassis (with different face and minor changes) as the Athenatech A301 series. The Athenatech was available with 80mm and 120mm fans while the Silverstone only came with 120mm fans. Yes, 120mm intake and 120mm exhaust. Zero cooling problems. Case is also wide enough to fit pretty much any CPU cooler.
EDIT: I just saw this SuperMicro mATX case (listed with server chassis, so never saw it before).
http://www.newegg.com/Product/...x?Item=N82E16811152123
http://www.supermicro.com/prod...wer/731/SC731i-300.cfm
A bit large for depth at 16.75", but pretty narrow and short. This takes normal micro ATX boards with two 5¼" and one 3½" external bays, but here's the interesting parts: FOUR internal HDD mounts and all four motherboard expansion slots can take full-length cards!!!
It also comes with a 300W PSU. Now, before anyone disses an included PSU, this unit is not meant to run a graphics card, just a bunch of HDDs and integrated graphics. That being said, the PSU has PFC and is 80+ Bronze!!! This is probably not a crappy unit (just low wattage).