Hi,
A few things to concider, CUCM 10x can ONLY be installed on VMWare, so you need to choose between a UCS-TRC, (tested HW from Cisco), UCS specs based, (Cisco HW but it is up to you to make the config work), or use 3rd party HW and in this case TAC will only check on the CUCM App, for the upgrade you can basically take a DRS backup and build a paralel server, upgrade that up to 8x, then move to VMWare and then upgrade to 10x, another option is to use BAT to export / import as much info as you can, (this will require you to modify the csv files), Please notice that Cisco does not recommend to build a CUCM 6x on VMware.
I'd suggest to contact your account team and ask them for the 'Drive to Collab' option, see:
http://www.cisco.com/web/solutions/vnlanding/comm_manager_upgrade.html
HTH.
Chris.