Bendix is making some really nice semi-met pads that cater specifically to street-pounded cars. I currently have ceramic pads (I forget which brand, they were quite expensive) and Moroso rotors, but the pads tend to glaze and the rotors blue from the heat of the ceramic pads. I was getting some serious heat fade after about 8,000 miles of installing them with the 96 upgrade, but I remachined the rotors, scuffed up the pads, and the brakes bite as hard as the day I got them. I plan on doing this again as the rotors are super fat, but I don't think I'll buy another set of ceramic pads for my SHO in the future.
Ceramic pads generally require heat to brake properly. On a cold day, I have to warm them up a bit to get optimal braking. There is virtually no dust and the pads are super hard, so they last a long time. On a humid day, some squeal can be heard, but with ceramic pads, that is normal. If you go ceramic, get the best rotors you can find and do NOT buy the cheap ceramic pads. Cheap ceramic pads only have about 5% ceramics in them, brake poorly on a heavy street car, and cause a lot of noise and squeal. They also have a tendancy to have hard spots in the pads, which will groove your rotors.
Also, you can not tow or haul heavy loads with ceramic pads.
To pick your pads, you have to state what you plan to do with the car. Daily driver and occsional trips to the track? Go semi-met high-performance pads from Bendix or Raybestos. Daily flogger and weekend track car? Go ceramic.
Pads must also match your rotors. For ceramic pads, a vented, slotted rotor would be best. If you go with semi-met, a vented, cross-drilled rotor would be best. A vented, cross-drilled and slotted rotor would be fine for either, but are generally very costly. Be careful when buying cross-drilled rotors, however. I have seen cheap cross-drilled rotors actually break and crack.
Stay away from scintered materials designed for the track. These are NOT suitable for the street because they require too much warm up and will NOT bring you to a reasonable stop on the street!
EDIT: I just noticed you said "stock 91 brakes." Do not use ceramics with these. The stock calipers are too small and cannot handle the heat. It will create too much mechanical fade. You need the '96 upgrade for ceramic pads. The calipers are much beefier.