David Stewart asks for reccomends.  There will probably be a slew of them,
by people more knowledgeable about different versions than I.  But...

Personally, I was introduced to the SMP with the Gardiner and I like it a
lot.  The Harnoncourt IIRC is -way- slower, and although Bach's wonderful
harmonies are drawn out the motion is lost a little...Gardiner does use boy
sopranos for the ripieno parts, but the chorus is mixed.  I also hear the
Herreweghe is good but I don't know it as well.  The opening chorus should,
as you say, convince anyone that this grand work is worth getting to know
intimately.

Bob K.