2014 F150

I have been looking at getting a newer truck( I currently drive a 1999 Tacoma) and I have a friend of a friend that is selling his 2014 F150 3.5L. Cosmetically the truck is almost mint and is loaded with options. Mechanically however, it has started with the cam phaser/ timing chain rattle on start up. Truck has 190,000 miles. are there any other common issues I need to watch out for? I would be doing all the work myself and with the price he is asking I would be willing to put 5-6000 into it to make it right. There is such a wide variety of options online so I just want to see if anyone else has a higher mileage 3.5 and people's thoughts on it.