What's your budget and what's involved in the emissions testing?
If you're emissions test requires a visual inspection, a new carb like the MC2100 may not work - depends if the testing center pays that close attention. If there's no visual, I agree with an MC2100 provided all of the pollution equipment (EGR, TVS, smog pump) is still there. If you go fuel injection, technically you're still supposed to have an EGR with TVS, but you can ditch the smog pump. You'll need a catalytic converter either way.
Let us know - I went with fuel injection because I had no smog equipment two years ago and passed. This past year they decided they were going to do visual inspections and I had to go back through and add an OEM intake and exhaust manifold, working EGR, etc. etc.
You may also consider a 4.0 head swap with MPFI, depending on how strict things are. The emissions place in CO said it was a gray area and was up to the inspectors if they would pass it or not. My guess is that half of them don't have a clue what they're doing anyway.