I would either get a timing belt kit from Rockauto, this should include the water pump and if it has one a belt tensioner, that or one from the dealer... don't really have an opinion on quality, but timing belt letting go on these interference engine's will kill it. wouldnt really go for one from ebay, but that's just me.
Temp gauge, my first guess would be that it doesn't have a thermostat, or the T-stat is bad... most likely, gauge, should be easy to check, but im not familiar with that model.
Srs light, on the 01 you should be able to use a scan tool and pull the codes, then go from there.
Hope that helps a bit.