Check voltage on the keyboard. Any adaptor should work. Pedal can get from any shops - Swee Lee, Yamaha, City Music etc. However, it's safer to get Roland pedals as some has reverse polarity (if I'm not wrong - Korg and Roland have opposite polarities).
As for amps, it's not recommended for home keyboard use (unlike guitars). Too loud and not defined enough. Monitor speakers are what you need.