My wife spent 74 days riding across the U.S., and several shorter tours using her front panniers on her rear rack. I'm sure you can do an overnighter with them. She carried her camping gear on top of the rear rack: sleeping bag, Thermarest, stuffable pillow,and running shoes.
A word of caution: Bike touring is addictive!
Pair of Ortlieb Packer Plus front panniers.
Good luck, and have fun!