Hey Sal,
Dont know of any good programs personally.....some people are partial to the Sample Tank program..you might want to check out that demo before investing....I personally think that nothing beats the sound of a Kurzweil...I have an SP-76(it also has Midi In/Out)..and use that piano sound over the ones in my Roland JV-1010 sound module!!...thats just my personal opinion....I think they go for around 600 or 700 dollars..but trust me...try one out in a music store..and you will love it!!
MM25
p.s. No, I dont work for Kurzweil or Roland so this aint no spam!!