Of course, I hate admitting this on a public forum, but I'm an Amazonian chick and the No. 6 Goliathe is the sickest board I've ridden, and I tried A LOT of boards. I asked Jay Reale from ebodyboarding.com to help me out, and he recommended it.
It's thick enough to float bigger riders, but it still has a good amount of flex in it. Too many "big guy" or "big chick" boards end up sacrificing flex.
No. 6 also stepped up the game with the Goliathe, and came out with the Goliathe Icon, a higher performance board for bigger riders.
Check out ebodyboarding.com, Jay would be happy to help you. Awesome site.