Don't know what you're charging but I hope it's a good buck because that floor is no bargain. Looking at the picture there is some serious lippage so chances are if you're going to take diamonds to it you might as well flatten it or the picture framing is going to jump out. I think you meant hall but you said hell and that actually may be closer to the truth in this case. Honing powder might help with the picture framing but you'll be sitting on it forever trying to blend it in. To answer your question you're going to to need a heavy machine that uses 220 or 480 volts because even if you were running a couple of granite heads you'll be there forever doing 9000 feet.
What grit are you starting with? Looking at the picture you can't tell how bad the floor is but you're going to have to bring it up to a 3500 grit finish and then polish it.I would try a tan pad with white granite polish and what ever your use to recrystallize marble, then power scrub it to remove the excess polish as a final step. Lots of luck and be careful because 9000 sq ft is a big job and you can get in over your head if your not familiar with restoring granite.
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Walter Nartowicz
Mid Atlantic Stone Solutions
www.midatlanticstonesolutions.com
4607 Fayetteville Road
Raleigh, NC 27603
919-772-2155 (Main Office)