Since I'm not such a huge fan of HB I would prefere the solution
"I put esx on both make them a cluster and house the vcenter VM on that two node cluster along with the vcenter for the development clusters? Using HA to protect the two vcenters?"
-> you have your own infra-mgmt cluster which is protected with HA including all VMs you need for running your environment.
Of course it depends on the availability level you want to reach, but in most scenarios a short outage of the vCenter (until HA kicks in) can be tolerated