I would not be afraid of a Koehring. I still run a couple of "off brand" Unit excavators (rarely on jobs, mostly truck loading in pits) and they have been good machines for me. One we have owned since new, and like anything else if they have been taken care of they are no more trublesome than a Cat, Hitachi, ect. As for parts most of these off brands use standard parts for example my Units have detroit engines and common hydralic componets. There are still sources for the uncommon parts for many of these less common brands, it just depends on how hard you have to look for them. You can get parts for a Cat or Hitachi easier, but they will cost quite a bit more in most cases. That said the Cat, Hitachi, Komatsu & others are very good machines, but I would not thow stones at a Koehring, Unit, or the other "off brands" - they were as good or some better in there day most even before Cat, Komatsu, or Hitachi were around. After all the dirt doesn't care what brand machine is moving it.