Maybe this thread should get moved to the discussion part.... anyhow I got mine in this morning. Looks nice - I've not yet had a chance to plug it in or anything. The specific model is 8835-Y11. The IBM Support page for it is http://www-304.ibm.com/jct01004c/systems/support/supportsite.wss/selectproduct?familyind=5151170&typeind=5151232&modelind=5166413&osind=0&brandind=5000008&oldfamily=5151170&taskind=2&continue.x=48&continue.y=13
Also IBM does have a doc specifically about setting this machine up as a VMWare ESX Server at the link above on the Install/Use tab. I did open the cover on it and yes it does have onboard SCSI - you would just need a SCSI cable and 2 68 pin SCSI drives to switch it to pure SCSI. It does not allow for hot plug drives and I dont see how you could fit an adaptor on the end of a drive so 80 pin SCA drives are not going to work. The ram it came with is 2 dimms and there are 4 more dimm slots open plus two PCI-X slots. It could be converted to use SCA drives but you would need the little backplane board and a new front bezel. On the plus side the rails for installing a second hard drive internally are taped in the second drive bay. I only wish it would support a pair of dual core processors. Probably would not work but I should just try sticking a pair in.... I just dont happen to have a pair of dual core opterons laying around so for now thats out.
Rather than looking at IBMs docs, you should look at the VMWare docs about ESX. We DO have a full compatibility grid, after all