trailer weight for truck
The power will still be there, but adding a trailer changes everything. You won't have the rapid take off and stopping will be different. You also have to get use to the "off track" that occurs in a turn. If you haven't towed before, ask lots of advise before you head down the interstate at highway speeds.
The weights you have stated are what your truck is rated for. These ratings have been talked about here before. They are the maximum weights your truck can safely handle. I believe the 15400 is the rating for a fifth wheel. My personnal trucks are rated for 15700 with fifth wheels. (The ratings were up'd in 2002 or '03.) You need to factor in the weight of the trailer PLUS everything you put in the trailer, clothes, food, water, etc.
Any more questions, here is the place to get answers. Good Luck