Without prices and links, this is a rough idea only from me.
Check out other ram. Just because you are using SLI doesn't mean you need "sli" ram. From what I've seen, SLI ram doesn't make a lot of difference. Just get some good 2x2GBs ram.
I'm not 100% sure the SLI of 8800GT's is a good idea. You didn't list your monitors res, so I'm not sure what you'll be playing at. To save some money, get two 9600GT's, with 512MBs of ram if you can. Won't save a lot of money with this move, but it might help a bit. Depending on the price of your cards, and the price of the 9600GT with 512MB, this might make senses. (or not.) The 9600GT in SLI is about as powerful as the 9800GTX if my memory serves. Check toms for the article they did about it.
You don't need anywhere near this much power for the PSU. The 8800GT is a good chip, and doesn't use a lot of power. 30A on the 12V rail is enough for two of them. You can run SLI 8800GT's on most "name brand" 600W PSU, maybe even some of the 500W+ ones. Personally BTW, I wouldn't run an aerocool PSU. Get something with a better reputation.
Your a stranger, so unless you've been browsing the forums, you probably don't know my dislike for Raptors/AID-0 arrays. If you are looking to cheapen the price, ditch the raptor. Raptors make such a small difference to the overall performance of the machine. If you want the speed it provides, dump both the raptor and the external drive, and get the new 1TB drives that are out. They can be as fast as the raptor, while provide more space then the two drives you were looking at getting. It would probably be cheaper to, seeing as raptors and external drives are more expensive then internal drives.
So the moves I would make, with the limited info I have, is to move to a smaller PSU. PCP&C makes several good 600-750W PSUs, and might be cheaper then what you have. If that isn't enough, dump the SLI ram for something more common. Next to go would be the harddrive setup, get a single 1TB drive. Last, move the video cards down to the 9600GT.