Comes out to 1710 before shipping or mail in rebate, and has room for crossfire upgrade in the future.
Mouse, keyboard, and wireless card are up to you. It will perform quite well in most titles(except stuff like metro which really likes nvidia), if you need better performance you can stick another 5870 in and still be 1k less than that alienware system.
Wow... This right there shows me that i can totally beat Alien ware's out rages prices. I'm not a ATI fan but i'll see whats out there. I may take some consideration on using some of the pieces you have supplied me such as the mother bored combo.
That would raise the build price by $50 which actually isnt too bad for a better PSU and a stronger card, you can throw in a second in SLI and have some pretty kick ass performance and the HAF X will handle the heat just fine.