Goetze makes some good piston rings, as I recall the last time I shopped for them I had a little difficulty finding sets with a chrome top ring but eventually I did. They cost a little more but I have had better results that way.
A lot of guys don't install new sleeves and just lightly hone or bottle hone the old cylinders and call it a "rebuilt" engine. Then it burns oil after 5,000 or 20,000 miles and they blame the rings instead of their own incompetence. Got to consider the source of information. Most guys don't even know how to properly measure a cylinder and if they do, most likely they don't have accurate enough tools or experience to do so. The "that should be fine" approach doesn't cut it. Measure it cause it matters.
I have heard from some engine builders that years back the cast iron for some sleeves was sub-par and they had problems till they changed suppliers, ask around and find out what reputable shops use.
Take tare choosing a shop for the machining and follow Mercedes spec. for piston / cylinder wall clearance, ring end gap, RA on cylinders etc... and you should be fine for that part of the engine. Good luck!