virtually every choice you make vehicle wise comes with a trade off somewhere, even if it's something as simple as cost. Bigger truck may be better for towing, but not necessarily even possible to park in areas you may want to travel without the trailer.
Most newer 5ers have nose caps, and extended pin boxes that help when towing with a short bed truck. You can still hit the cab though so the responsibility is on you to watch and not let that happen. Bumper pull folks deal with it all the time, although generally the damage isn't quite as much if you jackknife a bumper pull.
Keep in mind that with a short bed truck, and a long pin box 5er you could end up hitting the inside of the tailgate with the back of the pin box if you use a slider hitch, it's another area you have to look in to. In the end, you just have to look at the potential issues you'll run into with whatever combination of truck/trailer/hitch you end up with and make sure you never operate outside the constraints of that combination. Sounds easy enough, but it's also easy to get distracted and have a bad day.
As to the magic answer, in the end it's whatever works best for you. Good luck.
2015 Ram 3500 Laramie CTD, 4X4, AISIN, B&W Companion Puck Mount
2016 Heartland Bighorn 3270RS, 1kw solar with Trimetric and dual SC2030, 600 watt and 2k inverters.