Recording a piano depends on lots of factors, the mics you have available, the type of piano, how the piano itself sounds, the room you'll be recording in. Pianos are so grand in their soundsacpe that you don't really hear the full sound until you're a few feet away. You could try it with one mic set to omni. You'll probably need more velocity layers than that, atleast 7 I'd imagine, think ivory has 10(?). As for making a library, yeah Kontakt will be fine for that.
"Those who play for applause.... That’s all they get." - Wynton Marsalis