Best Configuration For Large MSSQL 2K5 Server?

Hey Everyone,

I'm building a new PC for a set of very large MS-SQL databases (currently weighing in at approx 5TB, and should grow significantly going forward as well). This is for personal business-related use -- I do not have access to a database expert, I am not in an enterprise (self employed), etc., so I am turning here for help.

I'm wondering what type of machine I should get to handle this type of database. It will not particularly be under particularly heavy load (just a few simultaneous connections, not too many queries running at once), but is obviously a very large database (with over 22 billion rows of data). I don't know what type of hardware setup would be optimal for this machine (mainly processors).

What I have spec'd out at the moment is:
11 * SAMSUNG SpinPoint T Series HD501LJ 500GB 7200 RPM SATA 3.0Gb/s Hard Drives
1 * ASUS DSBF-D/SAS Dual Socket 771 Intel 5000P SSI EEB 3.61 Server Motherboard
1 * Areca ARC-1220 PCI-Express x8 SATA II Controller Card
1 * Kingston 4GB(2 x 2GB) 240-Pin DDR2 FB-DIMM DDR2 667 (PC2 5300) ECC Fully Buffered Dual Channel Kit Server Memory Model KVR667D2D4F5K2/4G
2 * Intel Xeon 5060 Dempsey 3.2GHz Socket 771 Active or 1U Processor Model BX805555060A

Priced on newegg, comes to a total of $3638.34

In the <$4000 range, can you guys think of anything that would be superior? The 11*500GB's I want to run in RAID50, and the Areca card seems to be one of the best on the market (not to mention has 24 ports for future scalability). The RAM is FB-DIMM's, Xeons..... am I missing anything?

Also, I'm a bit concerned about performance on the Xeons. The ones I chose are dual cores. Since there arent going to be toooo many simul queries (really, often, prolly 1 at a time even), should i try for single core processors?

Anyways, thanks for the help.