You have many options available to you.

The first thing to do is determine what your maximum tow weight is, for that truck.

Also consider, what the total gross vehicle weight is, that is, the weight of the truck, plus cargo and passengers, plus the tongue weight of the GN - which is considered "payload". 

Last is to consider the gross combined weight allowed for the truck. This is the weight of the truck, payload, and the loaded weight of the trailer.

Those are your numbers to use when shopping for a trailer. 

How big your LQ is depends on what you'll be using the trailer for and how much you want. A BIG consideration is to work with a dealer that is straight forward and gives you GOOD answers. Sometimes the weight given for a trailer does NOT include the added weight of the LQ being finished.

3H with LQ alum trailers will give you the lowest empty weight.

I'll be back later with the website for the towing guide. https://www.fleet.ford.com/showroom/rv_trailer_towing/default.asp

YOu need to know how many doors your truck has and what size bed, (5.5 ft, 6.75 ft, or 8ft) and 4WD or 2wd. 

Look in your owner's manual and you will find a chart, that will tell you exactly what loads you can carry and pull. With those figures, you can shop for a trailer that fits within those specifications.

Gard

Tina

You should be able to pull a 3 horse with an 8' lq (or smaller) without any problem.  Happy trailer shopping.  I pull a Merhow 3 horse with an 8' lq that has a slide out with my Dodge 2500.