A Mac Mini Tops out at about 900 bucks with a gig of RAM, DVD-+RW, and a 1.42 Ghz processor. But i'd wait untill Mac switches the Mac Minis to Intel. By then they should have completed FrontRow and changed their RAM to 667 Mhz DDR2. They say that the Mac mini will come with some sort of new Intel dual core processor, room for 2 gigs of RAM, and come standard with an ATi X1300 Pro with no price changes. You could wait for that or get a PC.
Oh, 34erd, that is a wonderful system you put together. But I've always loved Samsung's (Or Seagate I don't remember) Spinpoint drives. 2 160 gig Spinpoints in RAID 0 would be expensive, but It would be totaly silent. I just got to play with a 80 gig Spinpoint, and it was silent and quite fast.