Don't go with i5 and i7 for Servers - Xeons are being produced for a purpose.
The desktop Intel CPU's like i5 or i7 are not designed to work 24/7, they ussualy have a shorter lifespan and lower tolerance when working under full load due to that fact. Other important thing is RAID-10, or at least RAID-1.
Also remember about some backup servers, just in case to rsync to-from.