As always, there are probably dozens of answers to such a question.
From my experience: Yamaha have the best standard piano sounds I came
across. Take a look at there motif or mo modules. Careful: There are keybaord
versions and rack versions.
Roland's XV series is very handsome. I played them a couple of times and was
never disappointed.
From my experience Korg lacks te piano quality of the former two.
Besides that, there might be componies specialising in piano sounds. With a
Yamaha or Roland you would of course get much more than piano.
Regarding Yamaha though: They have a good e-piano series called CP, perhaps
they also have simple sound-modules without keyboards attahced in that series.
Thiswould acutally suite your needs pretty accurately, because they just offer
grandpiano, harpsichord, Wurlitzer, Rhodes, 2-3 organs (hammond and church),
strings, choir, guitar and bass.
HTH.
Kindest regards
Julien
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