G'day...
I currently run a cluster(s)s of ESXi (& VM Infrastruture) servers, and have vCentre setup, so I should be able to create and add in your servers/DC, and start to migrate them across etc. It all depends on your new servers configs and their hardware specs etc. eg, what processors ie, and if they had the NX/ND flag etc... Do you use a central SAN/NAS/ iSCSI or NFS mounts, or just local VMDK files on each host...?
As you can see, I am quite experienced at this...
My SysAdmin rates are normally $70/hr, but I have quoted $50/hr for this project..
I look forward to helping you out..
Cheers,
ScoutMaster