Hello I'm looking at 99 F-250 4x4 with a 6.8l engine with 195,268 miles. they are asking $6,800 for it at the dealer ship do you think it would be a good deal? I'm thinking about trading my 2001 f150 for it and it haves 180,000 miles on it and would my hid headlights fit in it from my truck?

 

They would have to pay you the difference in that trade. You would be trading down.
Remember, they are looking for resale VALUE and your current truck has more resale value.

1999 to 2004 headlights are interchangeable. So YES they would fit

 

I didn't think about the resale value, I was looking for a truck that can tow a 1964 mercury Monterey the car weighs 4200 lbs

 

You sure found it in that 1999.
If you do go for it? Go in showing more interest in a newer model of truck... waste some of his time on a trade for that newer truck.
Then jokingly ask about a trade for the 1999 He may not think you are serious... but casually get him to give you a few details on that deal still giving him the impression your joking, then (If it is a good deal) say you will take it