Edit: Missing hard drive, optical drive, and OS. I'm assuming you have that covered...
I would recommend getting a HAF 912 for the case if you have an extra $20 that is. It gives plenty of space for airflow and upgrades. I have the challenger and it gives me very little space for a hyper 212 evo and a Radeon 6870
I personally like the challenger. I used it for my work, for a budget video editing system and it fit a refurbished NVIDIA PNY GTX 470 along with a Firewire PCI card okay. I also loved the way the hard drive mounts where setup but honestly, if I had the extra cash in the budget for my works build I probably would have went with the Cooler Master case as well.