Hi amindu,
I can’t make any specific suggestions because each person can be very different from others that have a similar body type and sleeping positions and I also don’t know anything about the materials in the mattress that will be under your topper (different mattresses will change how a topper feels) or have any reference points for mattresses that you have slept on and done well with so I would use your own sleeping experience and the topper guidelines I linked to make an initial topper choice (which you may need to exchange) that has good chance of success.
Based on your weight and on “averages” I would tend towards a firmer topper because higher weights tend to sink into materials more deeply than lower weights so they will tend to feel softer than they would to someone that was lighter but that may not be as good a match for your partner (if they are lighter they may need a softer topper) and not everyone fits inside the “averages”. I would also lean towards a 2" topper but your own experience will really be the only way to know whether a specific topper on your mattress is a good match for you.
I would also keep in mind that Dunlop can feel firmer than the same ILD in a Talalay topper (there is more about the differences between Dunlop and Talalay in post #7 here).
Phoenix