Volvo makes the most comfortable seats in the auto business, it's a fact. Auto reviewers love them and owners love them. The Volvo XC60 should be fairly quiet and has room for four.
My Mazda CX-9 has excellent seats also. My model, the top-of-the-line Grand Touring, has 20" wheels/tires that generate some road noise, but the mid-level Touring has less aggressive 18s that are much quieter.
I'd also look at the Lexus RX and GX as well as the Acura MDX.