I have been looking at the Cisco documentation and I am slightly confussed about using third party hardware for UCCX 8.5 on VMWare. The UCCX support matrix just lists UCS for virtualization so I think it is not supported. But the docwiki has a section "Spec-Based VMware Hardware Support which implies you can uses different manufactors hardware but performance issues and the hardware will not be supported, see http://docwiki.cisco.com/wiki/Specification-Based_Hardware_Support. As long as Cisco TAC will support the UCCX application itself I am happy.
So the question is will Cisco TAC support the virtualized UCCX application even if it is running on third party hardware (Dell in this case) with VMWare? All issues with the hardware, VMWare, performance are understod to be the custiomers responsibility.