hi,
I'm unclear on what you mean by Client to multiple TVs. If you mean multiple devices getting video and Audio from a central PC, then the PC should problably be referred to as the Media Server. If this is what you mean then thare are lots of options depending on the capabilities of your devices and your home network. Some TVs, PVRs, bluray players, game consoles (eg PS3), AV receivers can be DLNA capable, either as a player or renderer or both. If your devices aren't DLNA compatible then installing a WD TV live or similar device & connecting to the TV & Amp is one solution, using another PC as a MC client is another. For some a long HDMI cable from Media Server to Amp or TV does the job (ie not using DLNA at all). For me the differing capabilites of the DLNA devices is what makes setup a bit complex.
One of the key benefits of JRiver MC is you can configure several DLNA servers with different settings that get your centrally stored content to the device in the the format it recognises. The configuration also allows you to manage what content is presented to the device (eg if you had a room for kids you could filter the videos based on rating (eg PG only, not R rated etc).
At my place I've had upto 6 zones configured, some DLNA, others local to the hardware on the Media Server. My TV and PVR are both DLNA compatiable (early DLNA versions) & I was never happy with the quality. I ended up getting a WD TV Live unit & it does the job well. That device is connected via wired ethernet. I had another WD unit used for audio only. It used wireless. For that device I configured another DLNA server, reducing the quality of the audio stream (to medium). It also worked well, but as the WD device doesn't do Gapless audio I ended up connecting a pair of amplified speakers to an audio card in the PC.
I choose to store my video content as MKV. I find MakeMKV easy to use & does a pretty good job. I like that I end up with one file. (There is a defect with the WD device - I think it relates to the PGS subtitle stream in the MKV container. As such I remux 1080P content with mkvmerge.) Other users store video as ISO or DVD rips and this works well for them. MKV is also good for TV episodes & allows easy use of the TVDB to get episode metadata
For audio I use FLAC. Again a preference that works well for me (although I use MC to make a copy of all audio files in a format iTunes likes so I can sync to Ipods).
To control what's going on I use Gizmo (on phones and a tablet)
Hope this helps & doesn't make things more complex
Steve