Ok,
TheMarineCenter.com got back with me.
They said
The Savaii rock is more shelf-like, than, for example, Fiji, but not flat shelf rock. It has a very gnarly texture. It's a little different from Fiji, but not necessarily nicer than Fiji.
Fiji rock is by far the most bang for the buck, and it's as nice as
anything.
Thanks for the info Mike.

I am still looking for the tonga branch. What is the best price members have found for bulk 50-60Lbs?