bcurrier, find another granite guy. I got a 12 x 24 piece that they cut to size and gave me a tour of their operation free for the asking.
leatherpoker, I have a marble from Tandy which is good, a granite counter top piece which, IMHO, is better, and a 12 x 24 tombstone that cost $55 that is flush mounted to my bench that I think is best. Price & availabilty and how dedicated you are to this hobby (substitute addiction or obsession here). If you don't want to sink a bunch of money, try the counter top option to start.