Hi Tonkan,
Why dont you keep using the P80. It is a pretty good digital piano with a very nice 88 note keybed. Just add the PSR1500 to get the rhythm and styles. This is the cheapest solution.
If you are inclined in replacing your P80, you could get the Professional Stage Piano the P250 for $1800 and add the PSR3000 for another $1400. This setup will give you all the basic functionality of any CLV/CVP series.
As Rikki stated, the only downside is it would not look as elegant.
Tapas