Classical Guitar Soundfont Suggestions

Can you update the sound font for the classical guitar to play Dolce and Ponticello? The sound at louder levels sounds very tinny and sloppy, not how a classical guitarist would play it. Also, I have a couple of classical guitar plugins. Is there a way to make them recognize things like slides and slurs? One of my plugins plays the notes as written (instead of an octave higher). Is there a way to transpose the midi up an octave without transposing the notation up an octave? Just asking. I love MuseScore.