Not knowing whether or not you want to stay within the manufacturer's ratings (GCWR, GVWR and GAWR), be aware that a 5th wheel transfers as much as 20% or more of its laden weight to the truck as pin weight, whereas a TT transfers 10% to 12% of its laden weight to the truck. Therefore, with the limited GVWR of a 2500, you'll find that you can pull a heavier TT than you can a 5th wheel without exceeding the truck's GVWR.
Now, if you decide you want to pull a 5th wheel, you're in good shape with a long bed truck since that should give you adequate clearance between the front of the 5th wheel and the back of the cab without the use of a sliding hitch. This pretty much leaves the field wide open insofar as hitch selection is concerned. Reese/DrawTite is probably the hitch you'll find most often, but a number of us use the B&W Turnoverball gooseneck with B&W's Companion 5th wheel hitch. This allows us to tow a 5th wheel or gooseneck trailer and still have a clean bed when neither hitch is in use.
The Prodigy is the Big Mac of brake controllers. Yes, it sells the most, but that doesn't mean it's the best - just OK, since it's an inertial controller. The Jordan Ultima 2020 (if you can still find one) is a truly proportional controller that applies trailer brakes as a mechanical function of the truck's brake pedal movement. The Brakesmart does the same thing hydraulically, but is more $$$ - it's probably the best controller out there, however.
Having owned both wood-framed and aluminum-framed 5th wheels, both have their strengths and weaknesses. The wood-framed RV is more prone to damage from water leaks, but the aluminum-framed RV is more prone to structural fatigue failures. I've never had a problem with either, but the market is moving toward aluminum framing. Having said that, a number of the top-line 5th wheels are still wood framed.
You might want to hang around some of the RV-oriented forums such as iRV2.com or RV.net to pick up some more input.
Rusty