I considered a NAS/Time Machine setup a while back, but I never really trusted TM because, at least in the early days, it seemed like a black box. The I figured Retrospect would do pretty well, and though I haven’t looked at it in years, that’s the next possibility for me. In the mean time, I use CCC locally to two 3T drives, and succumbed to Code42’s CrashPlan for Small Business wiles. Yes, I was unhappy when they eliminated the home version and jacked up the price, but they keep previous versions of files, which was the dealbreaker for me with Backblaze. Plus, their tech support has been outstanding. Whatever I (and you) do locally, reliable backups offsite are a must.
If you really want to go the local network/NAS route, Retrospect might be a good solution (full disclosure, I used to work at Dantz last century), but again, I haven’t looked at it in a long time. Love to know how well it’s working these days.