What printers do Internet labs use?

For small prints (e.g. < 10x15") commercial Internet labs like
EZprints, Mpix, Ofoto, Shutterfly, Snapfish, and so forth
use digital minilabs like Agfa d.Lab-2, Fuji Frontier, or Noritsu QSS.

But for wide format prints (such as panoramic or 20x30" enlargements)
there are only three brands that I know of:

Cymbolic Sciences Lightjet, models 5300 5500 and 5900
Durst Lambda, models 76 and 130
Chromira ???

Does anybody have any idea which of these the various Internet labs use?
Their websites say nothing about it.

Native Lightjet resolution is 200 or 300 dpi, Lambda 100 200 or 400.