Hi Dermot, I don't think the Plasma can take LUTs internally, so you would need an external LUT box regardless.
As we know, the HDlink Pro isn't working at the moment... Still waiting for BMD to get back to me with a solution. Nothing from them for a while now (since my previous post above).
The ColorBox is a re-badge of the eeColor box, which I have here on test, and it doesn't work either at the moment. I am working with the manufacturers on fixing this, but not working as needed yet.
The Pluto and Davio LUT boxes do work perfectly