I need a new build that will handle large amounts of multi-tasking (multiple large excel sheets, multiple internet browsers with multiple tabs, and ability to have all open and run moderately intense games)

First of all, I do not need a Graphics card. The one I have (GeForce 8800GTS) will work fine. Also, I am good with onboard sound, don't need a monitor, mouse, kb, or speakers.

What I want:

Black or Black/Silver ATX Case (would be nice if it were on wheels)
Intel i5 or i7 processor
8GB RAM or more
1TB of storage space (In RAID 1 config, so 2x1TB drives)
Additional 1TB backup drive
3-bay Raid cage for the front 5.25 bays (2 slots for my RAID and 1 slot for my backup drive)
All-in-one BD-R/DVD-RW drive
USB 3.0 (front and rear) + SD card port (front)
Win7 or Win8
Power supply that will handle it

<$725 if possible


Thanks for input!