Please forgive my ignorance on the subject,
but I am interested in using a hardware midi controller to gain the full power of the GS.
Currently, I have a yamaha PSR-520 as my midi keyboard.

Question: If I purchased a hardware midi controller with all of the necessary sliders,
how would this be used? More specifically,
would I, 1) record my midi sequence flat via the PSR-520, and then on playback start tweeking the sliders of the dedicated H/W midi controller while somehow being able to record these overlayed slider movements in real-time?

OR would I have to 2)have one hand on the PSR-520 playing notes while simultaneously tweeking the sliders of the dedicated midi controller with the other hand ==> all being recorded to the sequencer simultaneously.

Also, should this dedicated midi controller be MIDI daisy-chained with the PSR-520 keyboard or should it have it\'s own midi port?

Finally, what, not so expensive, controllers are out there that can let me map all 16 GS midi controller parameters to a respective slider of the controller?

Thanks in advance.