Ok, let me ask you this. Will you plan on overclocking? How much do you want to overclock by? What other things are important to you? Are you an audiophile and like crisp clean sound? Do you require a monitor/keyboard/mouse with your setup? Although most people here will reccomend the DFI motherboard, it is not a motherboard for just anyone. It is extremely hard to get the perfect overclock with the DFI motherboard, and there are known problems like the coldboot that will drive you wild if you are not careful. The support people at DFI-street even say that If you don't want to worry about the little things, then get another board.
The MSI Neo-4 SLI looks good for the price, and has an awesome integrated sound, and also the option of SLI, which is always a plus. It also costs the same as the DFI Ultra-D,which does not support SLI. For the Video card, if you are getting an SLI setup, I wouild reccomend a NVIDIA video card. The three you should look for are the 6600GT, 6800, and 6800GT. These are priced at 160,250,and320 respectivly. If, however you are not going to get an SLI board, then I would suggest the x800 XL. This card is very very competative with the 6800GT, for about 70 dollars less. Yes, it does not have Sm 3, but even if games do support sm3 in the future, theyw ill still support sm1.1. Sm3 is actually meant to be eye candy, and will not improve performance at all.
There is however a third option. Get the 7800GTX. This card is awesome, and will play the next generation games just fine. It will however, take a big chunk out of your budget.
As for the ram, it all depends. There are many different choices, but I would personally go with corsair value select. For the money, it is a good cheap ram, and even if you plan on overclocking, the Ram divider isn't the oc killer that it is on pentium and ATHLON socket A systems. There are two other options that I will mention here breifly. If you decide to go with the DFI board, then the 105 dollar OCZ VALUE VX is good RAM to get. It will get tight timings, and will get good FSB with the huge voltages that DFI gets. If you get the MSI Neo-4 SLi board, then the TCCD OCZ Plantinum REV 2 1.1 will be the right memory for you. This memory is awesome, and will reach high FSB with loose timings and low voltages. These rams are pretty expensive though, and If you want to shave costs, get the corsair value select. If, however, you have the extra money, the two rams I mentioned for their specific boards are awesome.
As for hard drives, the Raptor will not provide a huge increase in performance. I would suggest that you get a IDE or SATA 150 hard drive and live with it. You can easily get an IDE hard drive that is 160 gigabtes for 40 dollars after mail in rebates. This will save you 120 dollars from the 10000 rpm hard drive, which you can use for a better grapics card/processor/ram that will benenfit you even more than the 10000 rpm drive will. Keep that in mind.
First things first though, will you require a monitor/keybaord/mouse? Or do you have those already? Overclocking or no?
6600GT PCI-E for sale/Trade. Check the FS/FT forums on tech-forums for details.