I've just taken delivery of a nice Tranquil PC T2e with a 2GHz Intel Core 2 Duo T7200, 4GB of RAM, a 500 GB disk and a twin head graphics card.
I hope to set it up as a virtual PC platform, running my main development system (Windows XP Pro) in a virtual machine, test systems and various flavours of Linux in more virtuam machines.
I initially installed CentOS 5 with the Xen kernel to host the VMs.
However, I was struggling to get dual head working with the ATI Radeon HD 3450 graphics card in the machine - as soon as I used the GUI to tell X Windows to use dual head, X stopped working. Hacking xorg.conf to use the ati drivers that come with CentOS caused an error message that it can't find an ATI Mach 64 card. The proprietary drivers from ATI fail to load with undefined symbols.
I solved this problem by getting an older ATI Radeon X600 card - the standard radeon drivers that come with CentOS understood this card, and it was then simple to get it working.