It's more of a personal choice for me, as I've seen a few reviews of those CPU's getting very near 4ghz with some decent air cooling on them. For gaming I believe that would leave the AMD in the dust if you were able to OC that to 3.2ghz+ which you should be able to hit even with a half-way decent CPU heatsink. Plus with that board you could nab a decent Intel quad core maybe 6 months down the road when Core i7 has somewhat matured and the older 45nm quads do a decent price drop.
You'd get a CPU that is stock clocked at 3.0 and a quality motherboard that has 8x/8x crossfire potential for the future. I'm not even talking about overclocking, at stock clocks the Intel E8400 would blow the 9600 out of the water. If you overclock........
The Coolermaster CM690 is a great case, the power supply is adequate, and it would power that eventual crossfire.
Go with the Asus TOP 4850, it's factory overclocked and cheaper at $140 after rebate http://www.newegg.com/Product/Product.aspx?Item=N82E168...
My best advice is be flexible and watch for deals. I got a $50 Intel combo 2 days ago at Fry's that normally goes for around $180. Never seen a dual core Intel combo this cheap. More to come on black friday.
It will give you the power to upgrade your Videocard in the future. Its $20 more expensive then the coolmaster, but you wont have to deal with rebates that make doing rma's difficult (just in case you get a bad one).
The Antec 300 case is well designed and possibly the coolest case in its price range, but needs 3 - 120 mm fans and 1 - 120 mm dust cover for the side vent to complete it.
Your Mobo is a solid choice. However, an Intel based build would give you lower power consumption, less heat (45 nm ) and a better upgrade path (775 socket is near its end but supports up to 3.2 ghz quad core CPU's). Consider this option instead:
As for the mother board you may want to consider something that is capable of crossfire. I've noticed that the 790X boards have been disappearing, probably to make room for dragon, but there are still plenty of 790GX/FX boards out there, like this Biostar board that comes with a CPU combo consisting of that 9600. Of course, I'm partial to a Gigabyte or MSI board myself