In search of the one Grand Piano Soundfont to rule them all *PLEASE HELP*

Hey guys, this is kind of embarrassing for me, but im a first-time poster and I have had MuseScore for a few months now. I'm REALLY dead set on making my own compositions, but for this one original work I am trying to do, I hit a snag....

I want to create a piano piece. I have this BEAUTIFUL melody in my head, beautiful chords, everything! It's already about a verse or so completed score-wise, but there'd just one problem...i'm not satisfied with the quality of the Piano. it doesn't sound realistic enough with any SF2 I have tried! My composition isn't that complex--at least, no more complex than say, "Good Company" from Oliver & Company (From which i'd say my song draws at least some inspiration.) No soundfont I have come across gives the piano a full, rivh stereo sound like that I desire. I need something that sounds REAL. Not a keyboard, not a yamaha. A real, honest to God old timey grand piano, so I can fully bring out the tenderness of the song. Each one I try is either too muffled, meaning that even with the volume up it sounds like it's in the next room, or like a yamaha keyboard with an overiding sense of synthesizer to it. I'm looking for a nice, high quality sound that allows you to HEAR the elegance of the piano, not just imitate a similar sound.

I've tried SF2's from all around, and still cannot find the sound i', looking for....is this too much to ask of museScore? If so, what program should I consider? It is imperative to me that I bring this song to life, and while I understand we deal with synthetic music here, I know there are ways to achieve what i'm after.

ANY help would e GREATLY appreciated. :)