Tuners, coax, and antennas (in case you didn't know already):
I feed 14 devices, 13 TV tuners and 1 FM tuner:
Get a good outdoor antenna so that you have a strong signal and put it on a rotator. This is an awesome looking and performing antenna, worth every penny: Channel Master CM-5020
The 300 to 75 ohm transformer they include is decent.
Use Shielded RG6 coax (if one says low loss, go for that one unless you are only a mile from the broadcast antenna):
Search the web for "antenna rotator", chances are good the same place has the antenna and shielded RG6 coax. Amazon may even have all.
Get decent compression connectors. Search eBay for these by PPC (about $12 for 50 connectors): EX6XLPLUS
Tuners- Hauppauge's I've used since 2014 with excellent performance. I can't say their latest is decent as I haven't tried them. The models I use:
Search eBay for "HVR-1150"
WinTV-HVR-1250 (PCIe 1x)
Search eBay for "HVR-1250"
Stay far away from any network tuner (HDHomerun, etc.)
If you are under 5 miles from the broadcast antenna farm, you may want to use a smaller antenna to avoid tuner overload.
With my setup, I can get a TV station 60 miles away. I'm only 11 miles from the local antenna farm so I get very good signals.
Oh one last VERY important point. None of Hauppauuge's drivers for the above tuners work properly with Windows Vista, 7, 8, 8.1, or 10. You can't even get a single tuner working under Windows 7. Maybe things have changed with new hardware and drivers. I don't know. I use on my 2 recording boxes Windows XP 32bit SP3. One box has 7 tuners (one USB) and all can run simultaneously recording to a single 750GB drive (green model Western Digital from 2008, not a speed demon).
Forget WinTV, I use NextPVR, an ancient version too: NextPVR v2.4.3 with lots of mods done to the ASP.Net to make it behave, as well as about 15 apps in Lazarus, Dephi, AutoIt, .VBS, and use Videoredo's Comm interface and NTFS alt data streams. The latest NextPVR may work fine, but I haven't tried it. I built this system in 2014 and it continues to work very well over the years.