Looking to get something to use with the roland PK-5 foot midi controller I am buying. Here is what I need, and hope to spend 400 or less, used. I have no idea if I am out of my mind or not for the money, as I really know zero about them. What I need..... Must have midi in, to use with the midi controller I have Somewhat easy to use Decent array of sounds built in Able to quickly changes patches on the fly Either a 3.5 or cd rom to load new patches Sampling capabilities (not nescessary, but would be nice) Looking for something in the $400 range, used. Any and all suggestions would be much appreciated.....but not interested in analog synths at this time, due to options I mentioned above.