He is using some VST instruments.
it's 100% virtual instruments.
It is I think a stock Ketron style.

You know, you can route each track to an hardware synth or to a different VST

On this mp3 he is using this :

http://www.vilabsaudio.com/true-keys-american-grand
http://www.uvi.net/en/composer-tools/plugsound-pro.html
http://pro.magix.com/en/independence/overview.1012.html

But for now, don't spend your money

Continue disocvering your SD1000 sounds