I won't give you advice, but I can provide some pros & cons of each plan.
Traditional (A+B)+(Medigap) Supplement policy will provide you the greatest flexibility, especially if you travel within the US. There is no set network you have to use, you can see a specialist without a referral if you want. So there is no doubt you can keep your current Dr and hospital you like for treatment. There are multiple Medigap policies (supplement policies) to choose from. Essentially you pick how much financial risk you want to take with each type of plan available in your state. The premium cost for each plan is different, as well as the deductibles. So..if you decide you want a Medigap policy "N", it will cost you $x. If you want policy "G" it will cost you $y. Now....all the different insurance companies in your state will offer the same plans, with the same deductibles and benefits. You need to decide which "plan" fits your needs, and then shop it around among the different insurance companies because the premiums you have to pay will differ. Wife and I had plan N, and it cost us about $300 a month for both of us combined. You'll also have to buy a Rx drug plan (D) separately to cover drugs. And pay deductibles and co-pays for each.
Advantage (Adv) plans are also specific by state. They are a little more complex to compare "apples to apples". Some offer HMO coverage, some offer PPO coverage, and some might offer open type coverage with no networks at all. (depends on your state). Essentially Adv plans combine Medicare part A & B into one, (technically called "C"). Most Adv plans cover the 20% you would normally owe for medical services from Traditional Medicare (which your extra Medigap policy you bought above, would pay for). So using an Adv plan would normally eliminate the need for buying a Medigap Supplemental policy. And Adv plans usually provide for Rx coverage (at least for generics), plus some dental, plus some eye care, and in our state even provide for a gym membership to get you in shape. Depending on your residence location, you might even get back some or all of your Part B premium that is deducted from your SocSec check. (although I think is rare) The downside to Adv plans is that they are not "portable". So if you travel, or have residences in multiple states, you won't be able to use the Adv plan in state #2 unless you go to the ER.
We started with Trad Medicare A+B at 65, because we refused to give up our primary Dr. Recently, he became available under Adv Plans. So we switched this year to an Adv plan (ours is a PPO). My drug costs have gone to $0. I use the gym membership several times a week. Went to an Ophthalmologist with $0 co-pay, and we're saving the $300/month for not having a Medigap policy to pay for. We do not have any restrictions we can't live with easily. The hospital network we want is also available under our Adv plan. You just need to do a little research with your Dr. & hospital to see if they're part of the Adv plan you want, AND from the Insurance company you intend to use. My Dr. has a sign up in the check-in window that says he does NOT take (1 particular insurance co.) Adv plans, but he does for most of the others. So you would be wise to verify with your own Dr. if he'll take your plan & insurance company....if you choose to use an Adv plan at all.
Good luck! Let us know how you come out.