I have hauled big bolts before and the 5000lbs is way too low for the overall actuall weight. With a hoist and a full bed it will be around 8000lbs or more.
The trailer may be rated for the load, but there are a lot of variables that have not been said.
Such as tag-a-long or gooseneck, trailer brakes, 16' with a 4' dovetail, trailer and truck tire condition, weight tags on the truck?
And that is just a few questions.
The F-250 will do the job if you have enough power under the hood.
I will not haul anything over 5000lbs with a tag-a-long trailer.
Anything more than that and I hook up to the duel/tamdem goose rated for 20,000lbs.
F-250 with the 7.3 diesel 6 speed and 24,000lbs tags on the truck.

Here are some pictures of the one I hauled about 200 miles to a new friend last fall. With the twin cylinder hoist and the full grain bed, I know the truck was pushing 10,000lbs.

http://s893.photobucket.com/user/2-Ton/library/57%20GMC

Keep asking questions, before you take it on.

Don

1967 GMC 9500 Fire Ladder Truck
"The Flag Pole"
In the Stovebolt Gallery
1946 2-Ton grain truck
1946 3/4-ton pickup,
1953 1-ton pickup
1957 1-ton flatbed dually,
1954 Pontiac Straight Eight
Of all the things I've lost in my life, I miss my mind the most!