We're just back from our trip, the first week was at Wyndham Kona Hawaiian! They definitely have beach/pool towels for your use. I think there were 6 in the linen closet when we arrived.
We loved breakfast at Huggo's on our first morning in Kona, and then returned to go to Huggo's on The Rocks for dinner our last night before moving on to Kauai.
A couple of activity highlights for us:
1. Coffee roasting session at Kona Joe's (even a tour there would be nice, or just a stop for a coffee...which we did on a subsequent day)
2. Snorkeling Kealakekua Bay/Captain Cook, we kayaked in using rentals via this Groupon:
https://www.groupon.com/deals/bay-side-adventures-1 They couldn't have been nicer, I highly recommend this company!
3. as mentioned, the night snorkeling with manta rays! We used a Groupon here as well:
https://www.groupon.com/deals/my-kona-adventures Another great experience, they were so nice and the group size was small, which was sweet. We saw much bigger boats with so many more people with longer light board things - I felt lucky that we had chosen My Kona Adventures with 6 people per session. I was able to ask questions and talk with the diver that was out there with us, he was very knowledgeable!
We also really enjoyed the Aloha party at the resort, it was just the perfect little music and hula show with a few pupus. I was afraid it was going to be a backhanded way to get us to an owner update, but it totally wasn't.
I did get a parking pass, but it was fairly low pressure and because I had already made plans for activities it was pretty easy to say no thanks to their discounted offers for doing the update. They didn't pester us the rest of the week.
Have a wonderful time!!! I can't wait to go back!