A keyboard similar to the Yamaha PSR 640

hello, i am looking to buy a new Yamaha keyboard and my school has the PSR 640, which i really liked but i believe yamaha have stopped making. i was wondering if anyone knew which keyboard is the closest to the PSR 640 and what prices. Im in a band and would like to gig with it, as well as use it for practicing in my bedroom. Any advice would be most helpful. cheers