Vortex Sound Research

I'm a pianist and know next to nothing about synths, but would like to explore some new sounds in the music I make. Thus I'm looking for a synth. I still want to be able to play it as a piano so that I can play classical music.

The interface doesn't need to be very complex (don't need an excessive amount of customization) and portability doesn't matter, as it likely won't be leaving my room.

My budget is under $1000

All recommendations and/or advice is greatly appreciated!