Your Windows vCenter server or VCSA can certainly run on VSAN. Two important items to keep in mind: 1) vCenter must be up and running to enable and configure VSAN and 2) VSAN can only claim disks that are totally empty.
What this means is that you need to deploy vCenter to a temporary location (independent disk in one of your VSAN nodes, another host, etc) then migrate it onto VSAN once your VSAN datastore is available.
Since you have four servers available you have a few different ways to accomplish this. My approach would be to install ESXi on host #1, configure a basic single-disk datastore on that host and deploy vCenter on that datastore. From vCenter you can then set up your VSAN cluster with hosts #2-4 which will make the VSAN datastore available. Then you can migrate vCenter into your VSAN datastore, zero the disk you were using for the temporary local datastore on host #1 then pull host #1 into the VSAN cluster and claim all of its disks for VSAN storage.
I highly recommend having a clone or replica of your vCenter server regularly moved to alternate storage in case there is a major issue with VSAN storage (this comment actually applies to any VMware environment regardless of storage technology). In our case I do daily replications of our VCSA to an alternate ESXi host (with local storage) in our primary datacenter as well as to our DR site.
Your Windows vCenter server or VCSA can certainly run on VSAN. Two important items to keep in mind: 1) vCenter must be up and running to enable and configure VSAN and 2) VSAN can only claim disks that are totally empty.
What this means is that you need to deploy vCenter to a temporary location (independent disk in one of your VSAN nodes, another host, etc) then migrate it onto VSAN once your VSAN datastore is available.
Since you have four servers available you have a few different ways to accomplish this. My approach would be to install ESXi on host #1, configure a basic single-disk datastore on that host and deploy vCenter on that datastore. From vCenter you can then set up your VSAN cluster with hosts #2-4 which will make the VSAN datastore available. Then you can migrate vCenter into your VSAN datastore, zero the disk you were using for the temporary local datastore on host #1 then pull host #1 into the VSAN cluster and claim all of its disks for VSAN storage.
I highly recommend having a clone or replica of your vCenter server regularly moved to alternate storage in case there is a major issue with VSAN storage (this comment actually applies to any VMware environment regardless of storage technology). In our case I do daily replications of our VCSA to an alternate ESXi host (with local storage) in our primary datacenter as well as to our DR site.
You can also bootstrap vCenter on a single host: http://www.virtuallyghetto.com/2013/09/how-to-bootstrap-vcenter-server-onto.html http://www.virtuallyghetto.com/2013/09/how-to-bootstrap-vcenter-server-onto_9.html