I"d be very happy w/a pair of the new Vantages (<$3k). and a stud w/the Summit.
as for the list above, I've never owned any of the Quest line. that is a huge panel, and prob a 12" whoofer, at min.
the sound-stage on something like that must be unreal.
the downside...is $$
You'll read time and again that panels (MLs in particularly, lots to read out there) are transparent, and really react with the rest of the gear upstream....and you can take that w/a grain of salt. After all, it must be nice when you are a reviewer and have 4 or 5 $10k amps laying around to play with..., and that excludes the vast majority of us.
you
can cheap it.... if you do your homework and a lot of leg work looking for the right used gear. but big panels want big watts, and..in my experience, they respond to various "quality of wattage" signals strongly. I've had a few of the SL3/Sequal sized ML's and a lot of various amps. class A, A-B, B, D, T..., ICEpower B&O based systems, Tubes and various Solid State. It wasn't until I got into a pair of Odyssey Stratus Extreme mono blocks w/my last pair (Seq.IIs) that I really heard what they can do. And I *thought* I had them dialed in w/previous amps ...., the Stratos's were sort of in another class, and those ML's really responded. Like "BANG"...they wake up and you hear shit you never heard before. An entire different dimension in the presentation, and the woofers will come alive big time. Dramatic !
so..., my point is...if you (the reader) ends up w/a pair of panels and are underwhelmed..., look upstream.