I have purchased the best Leslie simulator to ever hit the market and the best part is that I have adapted it the KN7000 drawbars. The sound is absolutely as good as this link. http://www.youtube.com/watch?v=zgXgjuH_kFc
Not only that, but the way I congured it, I am able to play other instruments and rythm at the same time.
Most arranger keyboards will send the organ section to "sub out", but not the drawbar section. The great KN7000 does, as follows.
Program Menue/Separate Out Setting/Mono X 2/Mono1-RH/Mono2-Left
Choose Digital Drawbars for each and turn off DSP or you will not hear anything. Using a Y mono cable, connect Sub Outs to an analog volume pedal and into a mixer channel. VOILA, a thrilling Leslie 122 sound through the drawbars. If you don't want to run the L and R1 through the Ventilator box, you can hit bypass, and play as usual. The rythm and R2 are going through the mains and are not affected.
You can Google "Ventilator Rotory" and come up with all kinds of information. It is imported from Germany at a cost of $450 to US.
I have tried all kinds of keyboards and Leslie sims, and nothing comes close to this.