Wig - Allow me to mention some equipment I like with the Avalons: I've used a BAT VK31 and VK75, neither SE's (which allowed me to try NOS tubes, which the Avalons like). Good combination. I'm now using a CJ Prem 14 pre with Mullards and a Prem 11 modified by Bill Thalman, which I think I prefer to the BAT gear (but it's all good). I wasn't that fond of ARC gear or VTL (at least the ST-160 amp) or transister gear with the Avalons. I think the Avalons sound best with "warm" and "forgiving" gear, personally, because they can be quite detailed and revealing (even amazingly so)...but it depends somewhat on your tolerance for knowing everything there is to know about recordings you are hearing (and I have some issues with that).
I've found that the EMM CDSA SE works really well with the Avalons, especially for classical music, but I also have a Great Northern Sound-modified Wadia that I tend to prefer for anything else. Both have very smooth top-ends and, again, I think that is good stuff for the Avalons (for my ear). Finally, I use simple Cardas Cross cable for all of my cable, including power...not their most expensive, but a very nice blend of revealing and yet warm.
Since I gave up the Vandersteens, I've run through 2 pairs of Harbeths and a pair of Spendor 1/2e's, all of which are very fine, but the Avalons, with the equipment described above, seem to give me the best combination of holographic detail-thrill, with musicality. I should add, though, that I also use a modest subwoofer made by Essex, which I got for use with the Harbeths/Spendors and didn't expect to use with the Avalons. Most people probably wouldn't use a subwoofer with the Avalons, but I got addicted to lots of bass, and find that a small bit of sub dialed in, even with the Avalons, is quite nice.
Best of luck!