If you still want to change your riding position to more upright fit 40mm riser handlebars.
Fitting a shorter stem and moving your seat forwards (effectivly shortening the reach) will bring your torso more upright.
Looking into this a bit deeper, all the options you have will help, but, they're dealing with the symptoms, not the cause.
Have you considered taking up yoga? You could increase your mobility, core strength, flexibility and much more enabling you to ride your bike as it is with no problems. ☺