Just so you know, all the folks here were huge AMD fans right up until Core 2 Duo hit the scene so you aren't talking to a buncjh of Intel fanatics who will give you bum info. We are all hoping that AMD hits one out of the park with the Phenom chip but right now nothing comes close to the Core 2 line up. It is so good that AMD just isn't in the game at this point as afar as the enthusiast sector. Plus Core 2's are relatively cheap.
That said, Phenom is coming out and although the info is sketchy it will be a very, very good chip. How good we are all waiting to see. The bad news is the intro won't be until early 2008, the good news is the Phenom will be AM2 compliant so you can upggrade later.
With all of the above in mind, if you are comfortable with AMD and you don't want to overclock then the 6000 is a great choice. Vegas has already built on that board and liked it so I think it is a good board foi you. Lot's of amenities and you have the option of SLI in the future.
If you do want to try and overclock a little then the 6320 is a better choice. That 9500 is excellent for overclocking a Core 2 as they run relatively cool. I suggested the 6320 because it matches your budget and will do 2.4Ghz with, more than likely, very little additional voltage. At 2.4GHz it will spank the 6000.
If you want to go SLI with an Intel, overclock a little and still stay within your budget then a really good choice is the Asus P5N-E SLI. It has a 650i chipset which means only 16 lanes of graphics PCIe total. Going SLI would split those 16 lanes meaning 8 lanes of PCIe per card but that is plenty of bandwidth for a pair of 8600 series cards, so not really an issue. The P5N-E SLI overclocks fine up to a moderate level but isn't a good choice for extreme overclocking. It also has two IDE ports, something that you don't see that much any longer, which means you can use those IDE drives with no problem. Best of all the P5N-E SLI is under $120
http://www.newegg.com/Product/Product.aspx...N82E16813131142Your RAM will work fine with the above gear and the P5N-E can handle your IDE drives because of that second IDE port. The P5N-E SLI with an e6320 will cost $300 shipped and I believe it will be an eye opening improvement over what you are running. With the 9500 you should be able to hit 2.6GHz very easily on the e6320 which will put it well above the 6000 performance -wise. SLI is your choice. If your card isn't strained now it will be in the futire and having that extra PCIe 16x slot gives ou the option of a real nice graphics boost later on at relatively little cost.
As always, there are plenty of folks here to help you learn how to OC when you are ready. Don't sweat the "noob" stuff as we were all noobs at one time or another and you'll never take heat here over being new to the game, we don't do that.