New Server

I need to purchase a new server and I wanted to know what you think of this.

These are the requirement
25-50 users
Exchange
3 users with high bandwith needs for graphic files. Currently using 130Gb of data. MS Great Plains
Win SBE2003

Please tell me if this is overkill
– 2 XEON 3Ghz
– 4x1Gb (1333Mhz) RAM
– 4x146Gb SAS or SCSI drives in RAID 5 with 2 redundants drives (room for 2 or 4 additional drives)
– dual nic.
– redundant power supply

Were talking 10-12k.
Opinions? Suggestions?
Thanks