iMica and aresone by clusteruk and phoenixkonsole respectively. As for business sense, I think most people are aware of the machines, although theyre more fan based projects by people who have a heavy interest in AROS than fully fledged big businesses. That said however the feedback by people who have bought them seems to be good, and they both have good reputations for after sales support. Both have also contributed a lot to AROS in general.
While I've built my own AROS machines over the years and arent really the sort of person to buy pre-assembled systems I must admit I do quite like the iMica silent machine, it looks quite nice, is tiny, and as the name suggests, is completely silent.
