hi
you can connect the tape device but its needs to be on a controller that in the HCL list and the tape also
in my experience i only got it working once but i couldn't vmotion the server cause of the pass through tape device, i just gave up and did a separate backup server
so even its a cost, the best way to backup is with 3th server
but if you want to save cost just use a good workstation. also works fine then.
veeam supports backup to tape but be sure to have lots of disk space cause its needs to backup to disk first before it can offload to tape
backup exec needs agent on the VM's. use the v-ray edition of backup exec.