Similar situation here. All of what you propose to do will certainly help. You might also consider a suspension stem for your handlebars. It helped me, even though I have front suspension.
The minimal design of the ShockStop Stem blends seamlessly with the aesthetic of modern bikes, while reducing fatigue and strain. Along with the ShockStop Suspension Seatpost, this system works together to suspend the rider and smooth out rough terrain on the bike you already own, making your...
redshiftsports.com
I had the best luck with Jones H bars that have a 2.5" rise.
View attachment 186838
The Jones SG 2.5 Aluminum Loop H-Bar retains the wide range of comfortable hand positions of the original Loop H-Bar, in a higher, 2.5" rise version.
jonesbikes.com
I found The extra 2.5" rise and 45 degree back sweep to be the most comfortable for me.
In place of rear suspension, I chose the Kinekt XR suspension seatpost:
Kinekt suspension seatposts smooth out the ride, no matter what type of bike you choose, or what type of terrain you are on, increasing in-the-saddle comfort and reducing back, leg, and hip fatigue, ensuring that you get the most enjoyment out of every pedal stroke, on every ride. All Kinekt...
cirruscycles.com
It's pricey but for me anyway, it's worth every penny.
I also have a Redshift Shockstop Pro seatpost on another bike and I find it almost equal to the Kinekt.
The Shockstop PRO Endurance Suspension Seatpost offers superior shock absorption no matter the terrain and no matter the bicycle. Perfect for gravel, adventure, road and MTB riders.
redshiftsports.com
My main complaint with the Redshift post is part of the suspension mechanism is located inside the down tube and it has to be removed to make adjustments. This also means the tube can't be shortened for custom applications.
Ergonomic grips, padded gel riding gloves and padded bike undershorts are also items that add a great deal of comfort. The right saddle is also critical but there are too many variations and personal preferences to mention here.
Every rider is different though, so what works for some, may not for all. I took advantage of sellers with a liberal return policy and used a trial and error approach to fine tune my level of comfort.
Good luck with your quest for the perfect ride!