Me, hypertherm, most people I know run hypertherm.
It comes down to cut quality and arc density, hypertherm spend a lot on development / R&D everyone else seems to trail behind on technology.
the technical manuals are very good too (I've only looked at air plasma side).
In Europe you'll end up with a CE marked unit (they are ever so slightly different internally, different noise filtering from what I've seen on the schematics).
Other brands are Thermal Dynamics of "similar" plasma cutters, a lot of the big bran welder companies also do plasma (eg Red/blue boxes Lincoln/Miller)
ESAB in europe will provide setups where as most of the others seem to be of USA / china manufacture, Im sure that there are Italian
Cebora (oops, thought they were Spanish!)
http://www.esab.co.uk/gb/en/products/in ... JcQAvD_BwEhttps://www.esab.co.uk/gb/en/products/i ... tegoryId=5It is worthwhile considering spares and consumables availability relative to the locality of use.
Not quite 12mm stainless, but there is a few nuggets of info here on 3/8" stainless + amperage required and improving cut quality (I'm sure there are many more posts on that forum too)
http://www.plasmaspider.com/viewtopic.php?f=3&t=26463