http://www.trailerlife.com/towratings/07towratings.pdf

By going to that site you can at least get your tow ratings.  Others can answer the weight issues vs. your axle ratings much better than me.  You should be fine as far as weight goes with a 2H trailer - from what I've read here, you'll need to watch the back of your cab with that short bed.

Good Luck.

J.M.

Check this site and see if you can find the info you need

http://www.fordf150.net/specs/

Unlike BP's, with any GN trailer, tow capacity becomes Four issues. Any one ignored will cost you grief, time and money.
1. Total loaded weight, Must not exceed CGVWR same as a BP
2. Hitch weight... The truck must be able to support the hitch weight a GN puts on the truck. The 3H trailer with only 2Horses MAY be worst than a 2H GN trailer because of the weight balance. Use the two front stalls and all of the horse weight is on the truck. If all the stalls are used, the last stall may be balancing #2... Air bags, helper springs and the like don't change the tires, axles, shocks, frame, etc... you get the idea.
3. Bed length. Depending on the shape of the trailer nose and the cab/ball distance when turning. A short bed is trouble unless you're very careful all the time. The various extenders are a help. Be aware the two types are very different loads on your truck hitch.
4. Bottom of GN and top of truck bed/tailgate clearance. GN trailers are designed to travel level. Especially with torsion axles, out of level will unequally load the tires and axles. You want to get at least 7 to 9 inches of clearance unless you are never going to cross RR tracks, road cuts, etc and stay on the level pavement always. A crushed tailgate is ugly.

I have an 2006 F-150 4x2 XLT 5.4 Triton.  When my girlfriend and I were looking for a gooseneck, went went to a trailer dealer who showed us a Logan 3H SL.  It was made to be pulled by an F-150, 1500, etc trucks...  It is narrower in the front so you dont clip the cab.  There is plunty of room in the tack area, but the nose is pretty narrow.  It was a new trailer, well 2005 but never sold, and it was around 17K. 

I think it is the Logan XTR 3H GN, but the photo wont load on Logans site.  But they do make trailers for our trucks.   We ended up going with a 2006 Miley 2H SL we found for sale on the side of the road for a great price.

No the manual is not helpful but here is a link to your 2007 Towing Guide.  https://www.fleet.ford.com/showroom/rv_trailer_towing/2007/2007_default.asp  Download the sections you need, but I would suggest reading everything in there, there is some good info about towing and safety and what you need to do.

Ford does have an excellent RV a Towing Guide that will give you all the specs. Most dealers have them. I was glad to see Ford offer the 6.5" bed with the SuperCrew and a larger gas tank. My brother bought one last summer and did the Popup 5th wheel conversion 9 inch gooseneck adapter and as been working well. Watch the bed rail height too, when you adjust the gooseneck stem length. Tall bed walls and now the 07 Tundra has them too.