Fabricator for large, thin porcelain tiles (4' x 8')

We are installing large, thin porcelain tiles (4′ x 8′) that look calcutta marble in our bathroom and shower. Our regular tile guy is very talented but hasn’t worked with these very large format tiles before and is nervous about cutting into them. Are there any special fabricators that work with these tiles and can do the cuts (for pipes, shower bench, etc)? Is this type of work typically done on site or in a shop (the tiles are currently in the apartment)?