I would say use just one vCenter.
Lets start with PROS of using 1 vCenter
vCenter can support all the hosts and its not a big number.
You will save on a vCenter and a windows license.
Lesser complexity.
CONS of using 2 vcenters
Management complexity increases.
Up gradation and other things get complicated.
A single vCenter can easily support 8 hosts. I have seen people using linked mode only when there are two sites.