I'm guessing you have seen www.penguincomputing.com and valinux.com. 
thelinuxstore.com carries some as well.

> I need to procure 3 rack mount servers.  In sorting through what is
> available out there I have found that
> most are RedHat based.  Whatever I buy, I will change to Debian.  The first
> server I want to have a hot
> swap raid array and dual hot swap power supplies.  The other 2 servers will
> not be connected to the web,
> but communicate data to the web server and do not need the raid
> array.  Does anyone on this list have
> any suggestions or caveats?