I use my DS918 as storage for my surveillance system. I think setup would depend on the system you intend to buy, and also how you want to set it up. I use Ubiquiti Unifi Cameras (4 in total). For my NVR, I run a windows VM that runs the Ubiquiti Video software. I use iSCSI between my server and NAS. So far I have no problems storing video or streaming it. I'm happy with it so far .
Synology has a surveillance application as well but I haven't tried it.