The only problem that I ran into when first doing my serp belt was that I needed an offset wrench. A regular wrench can't get the right angle because the nut is set into the belt tensioner.
Craftsman 5 pc. Wrench Set, Deep Offset Box End Metric
(These wrenches are also handy for loosening the top strut nut when doing suspension work.)
As for pullies... I don't think I've ever seen a lightened crank pulley that is still stock diameter. They are all underdrive. If you don't want your headlights to dim with a crank underdrive pulley, you should also get the alternator overdrive pulley. I've got the ZXtuner underdrive crank pulley and the overdrive alternator pulley. Both are very nice pieces.
Experimenting with different belt lengths isn't that much of a pain either. You just buy the next 3 sizes down when getting an underdrive pulley. For instance, a '96 Zetec Contour with AC normally uses a 4060735 belt. That means that it is 73.5" long. When you go to the parts store, get a 4060730, 4060725, and a 4060720. Just return the ones that were too long/short.