Price no limit...? Roland V-Piano
Personally, I'd shoot for more of a $1500 range, rather than a grand, as there are a lot of quality sampled pianos in that range... Kurzweil, Roland, Yamaha amongst many.
Budget ones... Ian likes his P85 a lot, Casio Privia is supposed to be a bargain, plenty of choice. And if you can't get to hear and play one in person, go to the PurgatoryCreek.com website, where most sampled pianos are compared playing the same MIDI file. At least you can hear them, if not play...
_________________________
An arranger is just a tool. What matters is what you build with it..!