I'd agree with Tostie, on the whole.

But with one important difference. Because arrangers like the Korg PA900/3X and the BK-9 (I can't recommend the PSR S950 yet, because it cannot loop the imported .wav's) can run .WAV loops alongside the arranger, the sky is the limit as to what you can do!

Bottom line is, the OP still hasn't told us whether this keyboard is needed for live music use, or for use in writing and recording. Or whether he is likely to want to do any other styles on it. If he does want to do electronica AND conventional music as well, possibly the arranger is the best choice, despite not being the best at pure electronica, especially if he wants a keyboard he can play out live on.

But if you are trying to do electronica just at home, I wouldn't bother with a keyboard at all! A dumb MIDI controller keyboard with a bunch of knobs and sliders, and then a ton of VSTi software synths would be the way to go, IMO. That's what most of the big boys use...