How does high-pass filter requirement affect system decisions?

You now have a world of amazing amplifiers open to you !
i ran my 5A with SS Ayre, a 1961MAC 240 and REF 75 tube amp.
and I use an Ayre VX-R Twenty with my 7 mk2.

There are a fair number of Vandersteen dealers who are also Audio Research dealers, the pairing of Richard's speakers and ARC tube amps being a long-time favorite. I've heard that coupling at many shows, and at length at Brooks Berdan Ltd. and Optimal Enchantment in S. California.

Agreeing with bdp24 above.  ARC, Ayre and McCormack are three brands that have often been associated with Vandersteens over time.  And yes, many Vandy dealers carry one of those brands.  I'm still struck by my interaction with Vandersteen 1ci and Quicksilver tube amps.  There was so much there there!

Interesting discussion.  I am awaiting delivery of a pair of Quatro CT and am beginning to evaluate my amplifier needs.  In fact I started a separate thread asking for advice on amp/preamp options with the Quatro CT.  I wish my Vandersteen dealer also carried Ayre as I am intrigued by this combo.  They primarily pair the Vandersteens with ARC amps.  As much as I am pre-disposed to SS amps, I am curious about the ARC REF 75SE.  I am thinking that 75 watts might be all I need...especially considering the high pass filtering will be relieving the amp of it's deeper bass duties.

Randyhat, Vandersteen recommends 40-200wpc for the Quatro's, so 75 should be in the sweet spot-especially if you are high passing to the subs.
I think one of the nice things about Vandy's is that they play well with a lot of equipment.
I am in transition to an Atma-Sphere amp and preamp with the Treo's. I never used tubes before, so this is going to be a new realm I'm entering. After 30 years, I had to give it a try.