2000 Camry (6 cylinder) has a Timing Belt not Timing Chain. Timing belt suggested replacement is around 60,000 to 80,000 miles. At 125,000 miles, here is what I can suggest if you have not change any of these parts before.
Replace the following: 1. Timing belt (very important)
2. Water pump and gasket (very important)
3. Two Idler pulleys
4. Timing belt tensioner
5. Camshaft front seal
6. Crankshaft front seal (very important because of the oil leak from oil pump )
7. Thermostat and gasket
8. Alternator and power steering pump belts
Do not save money by not replacing these parts and as much as possible, buy parts that are original/dealer or made in Japan. Sooner or later, at 125,000 miles, one of these parts is gonna break and it is a headache to be charged another labor when in fact the mechanic could have removed it before.
No. 8 (belts), you can buy the aftermarket belts, easy to replace.