Server Build ... Need your advice

Hi all.

Alright so i have not been following the latests hardware trend and all, but still know what is good. I have no clue as to pricing. Therefore i need your advice on building a server.

Requirments.
- Fast HD's
- RAID 1 ... basically need to backup SQL database
- Gig Ethernet.
- Drive space > 80GB.

Everything else is up in the air. You tell me what is good. Budget: $600

THANKS TO ALL