Brindle

Hi folks,
I've been to quote a job laying large 60x60 porcelain, with a marble insert. They have already had a big chunk of floor laid. Problem being slight difference in height between the two tiles, and some lipping that he's not happy with. Is there a company that can hone and presumably re-polish/seal the whole floor so it's nice and smooth. There is dirty grout too which I hope would be cleaned as part of this process.
Any pointers much appreciated.

Cheers
Bob