That is a server class machine, truth be told you won't find anything as powerful in a standard / gaming machine of the same era / price.
You'll need to check whether it has a PCI-e slot for a graphics card on the mobo as I doubt it will have decent onboard graphics (if any) as it is a server machine so it will have been omitted to keep costs down.
You'll also need to check for compatibility with whatever OS you choose, baring in mind it is designed for something like Red Hat linux which is server-focused as opposed to Windows 7 which might not have support out of the box for the RAID HDD config. I'm not sure what type of RAM they use, I'm guessing Non-ECC, but it's worth checking because RAM upgrades may cost more / less depending on this.
I doubt you'll need the tape drive ;) Although, for flawless Windows backups :D
To conclude, if it has a PCI-e slot and a standard RAID config - go for it! If anything it'll be overkill.