Well, i'm not sure where you've gotten your info about breaking timing belts, but I've been crew chief of a small road race team, and worked at performance shops for a very long time, and have never seen a timing belt break on any of our cars, even the 12 hour enduro cars that sit between 7 and 11 thousand RPMs with only 120 mins worth of down time for the twelve hours. The ussual reason for timing belts snapping is to much or too little tension, that and non-factory, poorly machined cam gears can also affect them.

As far as the TPS, you don't need to replace the whole throttle body, or even the TPS, you need to adjust it, in order to do this, you put a voltmeter on the middle wire of the TPS(for OBD2), and check the voltage, with a V-AFC or a comverted OBD1 ECU, it's ussualy right about .49 volts, but you need it to be right around .45V, otherwise you'll get an idle that surges, ussualy between 1000 and 1600 RPMs, it'll also tend to be jerky at low RPMs. You can adjust it by turning it clock wise or counter closkwise on the throttle body. Keep in mind from the factory that the TPS is rivited on there, and you need to either us nuts when you remove the rivets, or pull the studs and use bolts.

Personally I'd stick with the Power FC.

On another note, the Toda is close to a grand, not sure about the SMS, but the Hytech is 1300, if your gonna be spending close to a grand on a header, whats 400 bucks? Besides, like anything else, you really do get what you pay for. Either way, good luck with it!!

Aj