David prefers to play an acoustic grand piano, if available.
Or an upright acoustic piano, if it's in tune.
Otherwise, he will need a fully-weighted 88-key stage piano
The cheapest widely-available rental option is a Yamaha P-125.
The best ones are made by Roland, Yamaha, Nord, and Kurzweil.
The stage piano needs to have a working damper pedal and its own stand. In most cases, no piano amp is necessary if the piano can be run through the board so that the audience can hear it in the mains and David and the band can hear it through monitors.
Stage Plot for Shows with Band
Stage Plot for Solo Performances
Stage Plot with Upright Acoustic Piano