I do not have a lot to contribute based on the options that you have laid out except that it is the perfect time since there will be Ramadan offers soon. I am currently using the Dobinsons IMS and coil. Started using it since last Ramadan and relatively happy with it. But I do not off-road as much compared to some of you. IMS shocks allowed me to adjust the stiffness and I did request Dobinsons to make it less stiff as a compromise for on road comfort and I am happy with it. Although it is still stiffer than stock, no one complained when I ferry the family.
I think @Ale Vallecchi is running the Dobinsons Twin Tube. You may seek his opinion on the same.