Your timing belt is due to be replaced at around 80,000 miles, or whatever your owner's guide and warranty requires. Same thing with your water pump, which you should replace every second time you replace the timing belt.
At the dealership, the timing belt might cost around $500 alone but if you add the water pump cost (part only, since there is no added labor cost), you might expect a repair costing around $800.
Are you looking to replace these parts because of this other car you noticed overheating, or is the car you own having problems? Don't spend any money aside from the normal maintenance unless you are experiencing actual problems. Follow the maintenance schedule instead, that is costly enough.