ProAc D Two and an amp to live with forever

So, before the economy falls into the bottomless abyss, I likely have one chance to pick up an amplifier that I can live with for a long, long time.

I currently have a Naim Nait 5i powering what are clearly speakers I love. Really love. And the system sounds pretty good to me. But, I know from hearing other systems that these ProAcs can sound even better. By better I think I mean primarily richer, fuller and more lush. Not surprisingly, most of the systems that sounded better were tubed systems and I have never owned a tube amp.

The Manley Stingray has sounded fantastic to me the few times I have heard it, but I am unsure that it is the amp that can make the most of these speakers. If it is, that's great since its the cheapest option I am looking at now (cheaper suggestions welcome) and I am predisposed to like it.

The PrimaLuna Prologue and Dialogue are certainly tempting based on reputation, but I haven't heard them at all.

And the Cary SLI-80 from a feature standpoint have everything I am looking for (I think), including a remote and headphone amp, but I haven't heard this for more than a minute. This is also the absolute upper limit of my price range - in fact, this would likely be a used purchase, where with the others I'd look for used, but maybe buy new if I got tired of waiting.

I can, and will, listen to all of these. I can't listen to them with my speakers though due to the vagaries of local product line distribution. Home demo isn't likely to be an option since I am a recent transplant without any sort of relationship with the local dealers either.

Source is a Benchmark DAC. Music is jazz, latin, rock of the Tom Waits and Pixies sorts, and even a little Buck 65 style hip hop (and for those that don't know, this is more like Tom Waits than Jay-Z, but it still has some beats behind it that the kids like).

What else? Almarro and Audiomat have caught my eye at various times. And I have heard the Ayre integrated sound really good in several systems, but I am not sure it would get me what I think I want. That said, despite the longing-for-tubes set up above, at the end of the day I am looking for synergy and am willing to go in most any direction to get it. I would appreciate hearing from anyone with words of wisdom.

Thanks in advance!