Can anyone recommend an FM Receiver that would play into a relatively high end system?

Well I would certainly consider a Mcintosh MAC7200 as a high end receiver. I thought there were some other pretty decent integrated amps that had FM card options too.

I listen to internet radio a lot and have thought about getting a tuner for potential extended internet outages and to explore local stations. Using the phone on cell service is a great idea too, but that may become compromised as well in an emergency and watch your data usage.

I'd love to get my hands on a Magnum tuner to play around with. 

Many companies still make AM/FM dedicated tuners. Yamaha for one, see the link below. $250 new. You seem to already have plenty of amp and other devices, just need the tuner. I think that you can find tuners like this without needing to go some over-the-top complicated setup.
https://usa.yamaha.com/products/audio_visual/hifi_components/t-s500/index.html

I remember seeing an ad for a used FM tuner that could also receive satellite radio (Sirius/XM); but, I can't remember which brand(s) it was. But, if your goal is to have as many listening options as possible, that could be a potentially good candidate.

mitchagain

I remember seeing an ad for a used FM tuner that could also receive satellite radio (Sirius/XM); but, I can’t remember which brand(s) it was. But, if your goal is to have as many listening options as possible, that could be a potentially good candidate.

Several tuners have offered this option, including McIntosh, but it’s a poor choice. SiriusXM’s online stream is much higher audio quality than its satellite signal.

If you want good sound quality, provided you have good FM stations in your area, a dedicated high quality FM tuner (and a good antenna) can be an excellent source.  

Here's a great place to get info - https://www.fmtunerinfo.com/

I'm almost 50 miles away from the main broadcast towers and the sound quality from my Magnum Dynalabs Etude rivals CD playback.  I also have an Onkyo T-9090 II which is another excellent tuner. 

Most of the radio broadcast over the internet is compressed.  Radio Paradise is an exception.  Great sound quality and well curated tunes.

I've only experienced Sirius / XM as far as satellite radio goes.  It sounds awful compared to over the air FM broadcast.