I tried doing a forum search to find more information about AF-free credit cards that feature extended grace periods such as 60+ days, but sadly was unable to find anything concrete, so I thought it couldn't hurt to reach out to here to inquire, in this thread 
I know that there are technically AF-based credit cards out there on the market, like the Amex Plum Card and the Diner's Club card, but AFAIK, these cards also carry steep annual fees. I am specifically interested if anyone might know of any cards that offer the extended grace period, but are also free of having annual fees as well?
Just for some historical background info: the last card I had, that had a 90-day grace period feature, was my former Direct Merchants Bank Titanium card. Had it for about 7 years and paid almost no interest on it, because of the 90-day grace period feature on all purchases, which allowed me to revolve a balance *and* be able to avoid paying interest, at the same time. Unfortunately, however, when DMB was eventually acquired by HSBC, HSBC discontinued the 90-day grace period feature, and I felt I had no choice other than to close out the card at that time, due to a steep go-to APR for purchases. I still miss the card though, to this day...
ETA: correction, my DMB Card had a 90-day grace period, rather than a 60-day grace period; had accidentally mixed it up with the Diner's Club 60-day grace period feature.
You are talking 60 days from the day the statement prints? I'm doubting there is any card out there with those terms anymore. 25 days from statement print is now the standard.
-You are talking 60 days from the day the statement prints? I'm doubting there is any card out there with those terms anymore. 25 days from statement print is now the standard-
With the DMB card I had before, the way it worked was every single purchase made on it had a 90-day interest-free, grace period, so that you could both revolve balances and avoid paying interest, if you were able to time all of the payments so that you could avoid paying any interest at all. Very sad to hear that there are no products like that though on the market, today... 
I have my Chase Slate set up to do something like that.
It has a balance on a long term 5.99% offer that has a "minimum payment" paydown rate.
Chase has the Blueprint setup with some of their cards, you can add a rule that any new charges in certain categories (or all available categories) get PIF, added to the "Blueprint" payment, and don't get tagged with any interest. So that is one way to automate the combination of carrying a balance at an APR and PIF new charges.
The other way is to set up autopay, which will cover the long term carrying balance, and then figure an additional payment of any new charges, to just over-cover that, because those new charges will be in a higher APR tier, and after the minimum payment is covered, and pays on lowest APR items, additional payments over the minimum will work on the highest APR items first.