For the OP, I have a 2014 Express 4x4 black truck edition. I have the stock painted wheels and I'm running 295/60s. I also have the 3.21s :****sweak:8
I only rub at full lock, but it's minor. From my interwebz research a 1/4" spacer should clear it up. Right now I'm torn between keeping the stock wheels - which I love - and getting spacers or going aftermarket 20x9s with a +1 offset (5" backspacing).
As for performance, yes you are going to take a hit both in the feel and mpg. I just passed 11k on the odo and changed my tires around 2,500. When you first change tires, you really notice it. Now that it's been a few thousand miles, I don't even remember the feel of the drive before. Truck still has plenty of power to spin the tires. I just have to give it a little more skinny pedal than with stock tires. I went from 17-19 mpg and I could get it to 20 mpg when I wanted to. Now it's down to 14-15 mpg. That **** I do remember every time I fill up. But, it's probably more like 15 mpg since I haven't reprogrammed for the taller tires.
I hope to move up to 37s and 4" or 6" of lift in the next 2-3 years. I have no problems with minor trimming (or even major trimming) to get them to fit. I have time to plan it out - AND save.
Whatever you decide, good luck and post pics. Document your build so that the next person to do it has your thread to help guide them. I've noticed there aren't a whole lot of very detailed builds for Rams. I came from the jeep jk world, and there were TONS of detailed build threads with a whole lot of different combinations to go off of.