Unfortunately without VR UI you can't recover your replicas in case you are using VR w/o SRM.
In order to make sure that vCenter and VR servers are at good state you need to make them high available, either by VMware solution or by putting on available storage/host or by backing up them.
In the one vCenter scenario normally the source VMs are not located on the same host with the vCenter server. However, in case it is doable at all, I would recommend to have vCenter and VR servers on separate host/datastore that the source VMs or replica files