Not sure how long your trip is, but that prices out to about 2K per person. Not bad at all, and loved our stays at the GF (only done outer buildings).
I do think with the club level, any dining plan is overkill. Having the lounge to meet up for breakfast, drinks, evening appetizers, etc, is a VERY good call for your large group! You can provide flexibility for the group, and food and drinks (quite the value there) are already factored in. I would love to do GF Club level sometime, but it’s never worked out for us. AKL was fun years ago, and their evening appetizers were so hearty we only did two dinners for the week we were there.
Getting dining reservations for a large group can be challenging. Not sure if you are able to do so, but I’d reconsider the dining plan. Instead, if there is one paying person (sounds like you), you could provide each family group gift cards for their meals or some snacks. It would be easier to use the lounge for gatherings, then let each smaller group do their own meals otherwise. I’ve done a large group a couple times (I was the planner), and it is challenging! Almost to the point of needing a vacation after the vacation!
I’ve become a fan of the Chase Sapphire cards (hubby and I each recently got different ones). The sign up bonus was decent, and the perks are nice. We often travel on credit card points (almost always transferred to airlines), and hotel points (we each have a ton of Bonvoy points and he’s lifetime titanium). I’d recommend starting with The Points Guy, delve deeper (or more annoying if you want to read about rants from folks in first class not getting their desired pre departure beverage of choice) Flyertalk. I used to love my SPG Amex, but with Bonvoy, it’s not as beneficial to me. That kind of spend definitely would get you the sign up bonus; matter of fact, if you can break it into two payments, have your significant other get one too. Two bonuses. That would yield you at least 120,000 points. Transfer 1:1 to airlines of your choice.