Refined SS Stereo pwr amps under 10K?

One VX-5 is a great choice. Two is even better. A Theta Dreadnaught is another excellent choice. But if you really want your system to open up, get rid of the ML326 first and replace it with something like an Ayre or Aesthetix. Its a great preamp, but it won't allow you to fully hear what a new amp(s) can do. As long as you are not underpowered, a preamp upgrade should make a much bigger improvement in SQ than a new amp.

"09-13-14: 5560
For reasons too lengthy to describe, I cannot do monos, so I'm looking for a stereo amp. I've always read that Spectral amps require proprietary cables, odd input impedance matching such and they don't play well others so to speak."

If you can't use mono amps due to space issues, the Theta amp I mentioned in my first post is multichannel. As long as your speakers have 2 sets of binding posts, you can use 4 channels on it. I mentioned it because you brought up the Ayre V-5. The Theta Deradnaught and the Ayre are designed by the same person. I think the V-5 sounds a little better, but the Theta is a bit more powerful. I use the Ayre myself, so I'm pretty familiar with it. That said, looking at your system, I still feel a new preamp would make for a better upgrade. But that's just my personal opinion.

What is it about your ARC that makes you want to upgrade that component, as opposed to another? You'll probably get better recommendations if you provide more details about it.