Hi, my boyfriend plays the piano (classical and jazz) and for his birthday me and his family would like to offer him a digital piano. Our budget is around $600-$1000 maximum. Which ones would you advice in this list? I'm completely lost!

http://digital-piano.en.audiofanzine.com/



And if I decide to buy a second-hand digital piano, is there anything I should look out for? Which site is the best? Ebay? Any other?