Replace Case, PSU, and MoBo from XPS 410

I really hate my XPS 410. The cooling is one of the biggest jokes I've ever seen. As we speak, my 8800GTX is running at 65c. Also, I hate dell being all over my motherboard. So my plan for Xmas this year is to replace everything that I hate. My goal is to improve overall cooling and allow for decent upgrades in the future. I MIGHT try to overclock my Q6600 but it isn't a huge priority. I understand that my current RAM isn't very good for that but I might be able to swap it with 3 gigs of 800MHz RAM from another build.

Is there anything that Dell would have done that would make this very difficult? My plan is to salvage my 8800GTX, Q6600, and my RAM (2 gigs, 667MHz, DDR2 240-pin), disk drive, and hard drive. I have a few ideas of the parts I could use. I have a strict budget of $310 with shipping. If you want to give me some suggestions I'd be very grateful. Please don't suggest and items on sale or combo deals that would expire long before Xmas.

Here is what I have so far.

[url=http://secure.newegg.com/WishList/PublicWishDetail.aspx?WishListNumber=15856308][/url]

I really think I need to upgrade the RAM for the overclocking but I've never OCed before so I don't know exactly how that comes into play, just that it does. Will 800 be much more beneficial?

I worried about the RAM speed at first but after checking the manufacturer's website and a few comments on the board I found that it supports 667 RAM. Thanks on the advice with the overclocking. I'll keep doing research on it. I also plan to overclock and possibly unlock the 4th core on an AMD Phenom X3 720 BE that I ordered for an HTPC build that should arrive in about a week so hopefully I'll be a little more experienced by Xmas time.