Wheel offsets and tires size

getting ready to bag my ram and was hoping somebody would be able to give me a little insigt on what offset rims they are running on there bagged rides and tire sizes. right now i have 22" Oasis Gothics with i beleive a 15mm offset and 285/45 Nitto's that look like the will "almost" tuck without hitting anything but not 100% sure. Thinking about going down to 20"s with the correct offset but i have called OASis and they werent mcuh help on what i would need. Anyone have some info for me.Thanks