Q: Should I have a massive cooling system replacement done?

Engine overheated after never ever ever overheating. Water came out (I believe) of the radiator cap. My bad mechanic (who seems to just not want to work on my truck) said he wouldn't touch it unless I agreed to a 1200 dollar cooling system replacement. Wouldn't explain a specific problem, and the engine was still hot when he gave me the ultimatum. Before I left he put in a new radiator cap. I took the truck to my old mechanic (who I like) and said it had overheated and that the former mechanic wanted to replace the water pump and everything related. He came up with as price of 860, but seemed to focus on a leak in the timing cover gasket. Seems to be a "while we're down there you might as well replace the x and y" etc. I caught a doubling of labor charges on their write up and am sleeping on the decision. Bottom line: I'm a girl. Everyone says it's too big a truck for me. Bottomer line: I love this truck. Any advice? How long can I drive like this? Thanks!

My car has 180000 miles.
My car has an automatic transmission.