a city I visit frequently -or more precisely, it's exurban outskirts -
has only one mellow-Jazz FM-broadcast station, the only one for many
hundreds of miles.

thus I have decided to build my own single-station hi-performance
receiver to get the one station.

I know enough to know that ideally, the bulk of the gain,
directionality, selectivity should be at the antenna itself. Or even
more to the point, tower height. At least ideally. And
hi-performance single FM channel yagi's are easily spec'd from a
number of antenna houses. So that issue is not being placed on this
table.

The rest of the gain budget is.

Let the discussions begin. For example, what approach do the known
"name" receivers (Kloss Model One, GE Super Radio) use? can a
homebrewer do better?
Which commercial house builds the best resonant chambers for the 108
Mhz frequency? Can be be done easily at home? how about the
demodulation and audio portions?