Howdy!! Glad to see ya here...
I don't know what WW gets for a replacement carpet, but I'd go the carpet route again- they would be sooooo echo-y without carpet (and cold on the footsies also!
). But you could also just get remnant pieces or even a cut piece from any store that handles carpet- it's not that much money, and even better- a carpet shop can sew on the edging to make it look custom.
We're in the sand all the time also, but don't seem to have that problem. You can also just roll it up when you're out there- and if you lay the vinyl down, you'd have the best of both worlds.
Just my $0.02...