Get bigger tyres/move to tubeless and drop the pressures will probably be a cheaper/easier way to go.
If it's your arse you're worried about get a Suntour SP12 and Selle seat
Carbon forks and bars can make a big comfort difference, did on my old fatbike (On One Fatty Carbon fork and On One Knuckleball bars). Grips can help too, I fitted some On One foam grips, better than the default solid rubber offerings.
Recently fitted a set of 38mm Prime Primavera Carbon bars to my road bike and they are so comfy, even without tape.
If it's your arse you're worried about get a Suntour SP12
My hybrid is 27.2 and MTB is 31.6