Question: I would like to be able to play a piano or keyboard and have what I play stored and reproduced as musical notation. Is that possible?

Answer: 
Any keyboard that is MIDI capable can be plugged into a computer running notation software.

Although we don't offer recommendations for specific products here, just know that most electronic keyboards support MIDI, and most notation software supports converting what you play into sheet music.
If you expect the process to be fully automatic and the music you play is anything above the simplest - then NO it's not possible. You can get an exact reproduction of what you play, but you will not get even semi-professional results with the score notation.