Engine problem - stuttering

Well, I thought I had this problem licked. I cleaned the MAF with the right stuff on the second go round, and it all but stopped the stuttering. Then last week, it came back suddenly with a vengeance. It died 300yds from the house, and for the first time, would NOT start again. I tried 2-3 times hours apart, and still the thing wouldn't start. Had it towed to a reputable shop and they said it started right up for them . They've spent two days looking at it, but can't get it to act up again. In addition to the fuel system, they said they checked the plugs, and that they look good, but that their spark is orange/yellow instead of blue, and therefore think there's a problem with the distributor. I'm inclined to agree.

I'm wondering whether to let them shotgun the distributor (~$650 they said), or, because it's running, drive it home and replace it myself. Will drop by the Toyota dealer today and see how much they want for the part.

I'm also wondering if the problem is limited to the ignition coil. The distributor cap and rotor looked ok to me when I inspected it a few weeks ago (when I also resprayed the MAF with the correct stuff). Can the coil itself be changed independently? I've got a '95 2.4l. Bad ignition might also explain the rough idle (lots of steady vibration when stuttering problem isn't rearing its ugly head).

What does the cumulative wisdom of this panel suggest? I'm mechanically equipped and capable, but not experienced with more than basic maintenance on engines.