This one with Mackerras:
The earlier Mackerras on Telarc is a good example (to my ear) of a Telarc recording that was less satisfactory. The string sound is (to me) a bit edgy, which is annoying given that the strings are the name of the game. However, Mackerras is a good Mozart conductor, and I just ordered the Linn set myself last week. It should be excellent. And Symphony 40 is a "must-have"--one of the great works in the "canon."
A very nice budget set by is by Saraste on Virgin, which has several other Mozart Symphonies (though not 40). Lesser known conductor, but I liked this set.
George Szell and Bruno Walter were (for me) two of the great Mozart conductors, but their Mozart symphonies seem to be kind of hard to find now. The Walter set of late Mozart symphonies is available from Arkiv Music, but the Szell is only available is a big boxed set. And the recordings are a little bright (though tame-able, if you have tone controls).
If you like the symphonies, the next stop should be the late piano concertos. Many fine recordings...
Another variation is the Hogwood/Academy of Ancient Music "The Symphonies Vol.VI Paris & Vienna" on Decca (L'Oiseau-Lyre 421 085-2). It's an old recording from 20 years ago. What's striking about this is a smaller classical orchestra with period instruments giving the symphonies a slightly smaller sound - almost like a chamber orchestra - that the jacket says is what Mozart had intended. Good recording quality for the time and, I think, a very good interpretation with top notch musicians.
I suggest you consider the Karl Bohm 2 CD set of 6 Mozart symphonies on DG Originals; the 2 CDs are sold at a reduced price. The performances are among the best (if not period instruments) and you get 6 of the best known Mozart symphonies -- excellent for one getting to know classical music. Sound is decent, if not demonstration quality. I have multiple recordings of these symphonies, but these are the ones I listen to the most.
I have the Bohm, Mackeras,and Gardner and those are all very nice. Another very fine choice is Pinnock's on Archive - I have the box set but the individual symphonies may also be available. The interpretations from all of these conductors are very different from each other. Classical music listening is an incredibly endless and rewarding pastime - it can be an acquired taste for some - but well worth the time.
Thank you all! I truly appreciatre it. So many options...it was difficult to make A decission. Eventually decided to go with the Mackerras' by Linn, and I'm definitely taking note of the other recommendations and keeping in mind interpretations vary a lot.
Your guidance has been so encouraging you are likely to see further questions from me about diving further into classical.
On the strength of the recommendations coming out of this thread, I just purchased the Makerras/Scottish Chamber Orchestra set and am extremely glad I did (thanks!). I have several favorite versions of Mozart 39 and 40, and not to knock the excellent performances by Walter, Menuhin, Pinnock, Bernstein and Bohm, I have a feeling this will be my go-to set for late Mozart symphonies for some time. As a bonus, listening to the Makerras (twice) set me on a Mozart binge yesterday and along the way rediscovered Frans Bruggen and the Orchestra of the 18th Century's fine recording of the 40th (coupled with Beethoven's 1st on Philips). I'd forgotten how much I admire this version.