If you only want a piano sound it might be cheaper to get a controller and a used Kurzweil Micro Piano, 1080, or something. Plus there'd be more options as far as controller features.
I saw a cool Novation controller a NAMM. It has templates for Reason, Logic, PT etc. It also has touch pads, although they were rather small and laid out in one row.
http://www.novationmusic.com/product.asp?id=30&Type=1&bArchive=False M Audio, Korg etc also have controllers with touch pads.
I would think that you, Mr. Drummer, would have some stick pads for that sort of thing....TrapKat, Pad 8, whatever...... Those are way better than a keyboard for drum programing, while touch pads are just a little better.