EXCELLENT case choice. I've got the Cooler Master CM690 Nvidia Edition, provides A+ cooling. The RC690 you picked looks to be the same design, but $20 less than the one on TigerDirect:
https://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=4177133&CatId=1842
I would recommend that one from personal experience, but the RC690 should be more than capable of getting the job done. As for a PSU, go with either Antec or ThermalTake. I've got a ThermalTake ToughPower 750 Cable Management PSU which feeds plenty of juice to my mobo and GTX 295.
As stated by someone else earlier, go with AMD/Asus. The current board I have right now is the M3N78 PRO, and it's been a great board so far. I would highly recommend an AMD Phenom II X4, though.
As for video, you probably wouldn't need a GTX 295. I would suggest Nvidia, though. I have no beef with ATI, it's more of a personal choice. Though, again, as someone stated earlier, if you're looking for a decent, cheap video card, go with ATI. Something like this:
https://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=3529980&Sku=V261-3852
As for a HDD, I would suggest the Western Digital Caviar Black line. I've got two 750GB of these beauties, and they're great. They each have a 32MB cache and a transfer rate of about 115MB/s. I haven't played around with them in RAID, but will be soon. I can only imagine how much better the throughput will get.
My build cost me around $1700 (not including the monitor), BUT it's also meant for high-end gaming. the video card alone was $600, and I've got 8GB of OCZ Gold in it. You wouldn't need anything quite this powerful, but I would highly recommend a quad-core processor as it will help things move along a little bit faster. Hope this helps! :D
ADD: also, if you'd like a good heatsink, I'd go with this:
https://www.frozencpu.com/products/9539/cpu-cma-29/Cooler_Master_Hyper_Z600_6-Heatpipe_Universal_Active_Passive_CPU_Cooler_Intel_LGA_775_1366_and_AMD_939_940_AM2_AM2_AM3_RR-600-LBU1-GP.html?id=ctdusQ2w&mv_pc=12821&gclid=CPeL_I_g5ZwCFU1M5Qodrw30Hw
It tends to keep my Phenom II x4 940 at about 30 degrees Celsius. That, and the Arctic Silver 5 thermal compound. lol
AND, before I forget, you do want to keep an eye on the minimum PSU requirements are for the video card. This will be the wattage, along with what's on the 12v rail. If it says 12v1, 12v2, 12v3, etc..., just add them up. There are some PSU's that split the rails in order to help prevent the PSU from sparking and catching fire.