gotta warn you, you asked for analog and the korg ms2000 is not analog. its virtual analog, meaning that it has a digital processing chip that emulates the analog circuit of a real analog synth.
although they are arguably similar (as one is a direct emulation of the other), there is actually a huge difference. to sum it up, the tradeoff is as follows:
- VA synths, such as the ms2000 or ion or virus etc, generally have tons of crazy functionality that would be impossible in the analog domain... programmability on steroids
- analog synths sound amazing and "real" in a way that VA can never quite imitate. believe me, there have been attempts, and some people even claim that they have it down and their VA synth sounds exactly like an analog synth. but double-blind tests (given a trained ear that is familiar with analog and VA synths) will almost always show that VA is never quite there.
having said that, i would suggest that you look into real analog synths if you only are trying to use this synth for bass. this is because of A: the analog sound, and B: the fact that the extra VA functionality doesn't really help for programming bass sounds (where you will usually stick with basic sound design and not get all experimental).
http://www.vintagesynth.org has a great listing of synths, including all the classic analog synths.
you will probably need only a monosynth for basslines. the minimoog is a classic but its relatively pricey. a cheap alternative is the novation bass station, i think it costs no more than $100 used, and it sounds cool for bass stuff (avoid the non-bass harmonics). its used by some big names.... RZA, radiohead, havoc, massive attack, salaam remi, trent reznor, the list goes on.....