The tools to edit that piano are already under your fingertips The S900 is no synth powerhouse in terms of editing.., but adjusting those synth parameters and even EQ'ing will makea world of difference. I've played the S900 a few times and have messed with the patch editing. It's pretty logical and laid out fairly well.

When I played with the S900 I found the pianos to be to bright for my tastes. I adjusted (on the fly) the velocity settings, minute filter adjustment, and light edit to the effects and was pretty impressed with the result of the S900's piano with some simple editing.

I still say talk to a few guys here who have one.., tell them what you need from that piano and they can hit their 900's and share the file with you.., or download the file already listed in this post.