for the second part, consider paying the guys who
produce PianoTeq.
there are other options (such as LinuxSampler with a decent piano
sample library) but PianoTeq is just cool and they released a version
for Linux at the same time as their Windows and OS X release. worth
rewarding IMO. the program gives you *insane* control over the piano
sound - its physical modelling, not sample playback.
I just checked out PianoTeq. It's impressive. The only downside is
that it's 249 €, which is $350 (USD). I recently purchased my
recording gear, so am currently unable to put more money into things.
Perhaps in the future but I'll have to stick with open source for now.
Though thank you for the recommendation! :-) I'll keep their main page
bookmarked for future reference.