Your "friend" gave you a whole bunch of misinformation. Some outright wrong.
Ford, GM, Dodge...pick your loyalty. All the newer trucks are great towing machines.
Try to get a handle on the 5ers that you might buy. The newer 3/4 ton trucks can handle a lot but if you might go larger, look to jump up at least to the 1 ton single rear wheel models. They cost next to nothing more but they really boost the 5er rating available (pin weight not tow rating as pin weight is usually the limiting factor)
4x4: If you do a lot of off roading, get it but if you are asking that likely isn't the case (plus big trucks are lousy off road vehicles). Otherwise about the only occasional useful thing about it is using low range as a creeper gear. Otherwise, it's more cost up front and maintenance with worse MPG.