Thanks everybody,
That's a very interesting comment about the HCA-2. Not sure of why (technically) this is the case, but it's sure good to know.
I believe that Blue Circle's designer (can't think of his name) does use them as his reference. I think I'll shoot him an email and find out what he thinks.
MDL - The Power 2 is 110wpc, no?
Any more suggestions are welcomed. I really would like to stay with tubes if at all possible. In fact, the gentleman that I bought them from told me that he had good success driving them with a VTL running at 60wpc SET. Obviously not to particularly loud levels, but very sweet and 3D, according to him.