How about a Yammie DGX-300 or 500, that thing has a pretty good piano sound + Arranger features, Then he can enjoy the best of both worlds.
DGX-300: http://www.yamaha.com/yamahavgn/CDA/ContentDetail/ModelSeriesDetail/0,6373,CNTID%253D2711%2526CTID%253D205200%2526VNM%253DLIVE%2526AFLG%253DY%2526LGFL%253DN,00.html
DGX-500: http://www.yamaha.com/yamahavgn/CDA/ContentDetail/ModelSeriesDetail/0,6373,CNTID%253D2712%2526CTID%253D205200%2526VNM%253DLIVE%2526AFLG%253DY%2526LGFL%253DN,00.html
Greetz
,
Marcel