You are looking at two different kinds of rock.
There's mined (fossilized) rock. It is mined inland and hasn't been in the water for a gazillion of years. I am assuming it's all mined from the same place.
The fossilized reef rock is sold under different names:
MarcoRocks sells it as 'Key Largo'
ReefCleaners sells it as 'Florida Reef Rock'
BulkReefSupply sells is as 'Reef Saver'
In my opinion these three are the same type of rock and you can choose your supplier based on price or customer service (John with ReefCleaners is very nice and he's a MAAST sponsor) or whatever appeals to you -the rock will be very similar/identical.

MarcoRock also used to carry what they call 'Signature Fiji' rock which is carried under the name Pukani Dry Rock by other suppliers.
Pukani is from a current reef, used to be live rock but has been dried and cleaned and is being sold shipped as dry rock.
Different kind of rock.

If you are interested in the differences let me know. I don't want to ramble on if you already decided what you want but am happy to elaborate if you want me to ;)