There are a lot of good alternatives today in the price range of the Antec 900 that offer some better features. I would take a look at the CoolerMaster HAF922 and RC-692 II Advanced. Both have great airflow and better cable management options.
Swap that HDD for a Samsung Spinpoint F3, its cheaper and faster.
That PSU is overkill for a 9800GTX. Do you plan on doing SLI down the road? You would be fine with a nice 500-600 watt modular PSU, and for SLI/Crossfire, something like the XFX 750W PSU would be plenty.
If you are just gaming, save some money and drop down to the AMD Phenom II X4 955. Its a good bit cheaper, and will offer the same performance in games. For CPU cooling, I would look at the CoolerMaster Hyper 212+, its cheaper than that Zalman and very highly rated.
Other than that things are pretty solid. However, if this is a gaming build, that GPU is a huge bottleneck. I would say drop the SSD and use the savings from the CPU to get something like a GTX460 or HD6850.