I too had a ProLiant (ML570) which i couldn't install SuSE on. It has something to do with the raid controller that is built into the chipset. I even upgraded it to a Compaq SmartArray 5300 (Ultra2 160) and still no go.
If i can make a couple of suggestions:
WWW, Gateway, Firewall, FTP etc.
Clark Connect -- www.clarkconnect.org
Based on CentOS and is very easy to administer (web based admin)
Advanced "Do It Yourself" Server:
Any server app you choose
Based on Red Hat Enterprise Linux
Hope this helps!