i've actually been interested in doing the same thing for a long time, and found that for me it was easier to try to reproduce the sound using an actual synth. the Korg Ms2000 (or microKorg to a lesser extent) is really good for this because its got a pretty buzzy sound to it. the Alesis Ion is good, but you have to turn off one or two of the oscillators to get the right tone. square wave forms are usually best. as for sampling the sounds, i don't have a lot of experience there.