Medicare in Pa Sup ins

I am currently on medicare and Aetna. Aetna is my Husbands work insurance. they have an exclusion for WLS. Medicare will cover. Has anyone gotten Suplimental insurance to cover what medicare did not? I am lost is a sea of insurance policies and I don't know what to do I can afford to pay up to 175.00 a month for this insurance. I want the one that I will not have to pay a lot of out of pocket for this surgery.
Do I need to cancel my Aetna from Hubbys job to get suplimental?

Thanks for taking the time to answer these question if you can. I know I can always get answers on OH.