[hamiam]

While people will swear by a certain brand, diesel engines are, in general, a very hardy lot. The issues with them invariably come down to maintenance. All you need is clean fuel, air, and compression. Take a look at the engines in question; a quick visual inspection of the engine exterior alone will usually tell you how well it has been maintained. Also, ask the sellers how much they use the engine and in what capacity. IE you dont want a guy who never uses it nor do you want an engine that is being used constantly for a low level activity like battery charging. Diesels like to be run hard in general. So, in short, having owned 5 different boats with 3 different brands of engines, I would concentrate on the level of care of the engine and not the specific brand.