Let's try this a different way then


It appears my desired Maggies will not work in my 13x22x10 room, so I am now in search of the next best thing.

Which speakers (especially those listed on the marketplace here) under $1000 would be well matched to my Adcom GTP-500/GFA 555? Source is an Onix XCD-88 (Burr-Brown 1732 24-bit/96kHz DAC internal).

Musical tastes are folk, jazz, classical and 60s rock. As you can tell by the reference to the Maggies, soundstage and detail are more important than bass. Ideally, I'd like to fill the room with music and lose track of the speaker locations
kythyn
There's a pair of Joseph Audio RM25s for sale here for $800. Outstanding imaging/soundstage and they pull off a disappearing act that rivals the best out there. Will have no problem filling your room with sound. Jump on them. You won't be disappointed.
No planar speakers are going to, "fill your room with sound." Whether electrostatic or planar-magnetics; they are way too beamy. Done correctly; they do an excellent job of disappearing, as a sound source, but one must be seated in exactly the right spot to enjoy the presentation. You won't accomplish what you want(filling the room) with dipoles. An omni style system would be a better choice(ie: in your price range- Ohm).
Other than a higher ceiling, my listening room dimensions are quite similar to yours. I've used MMGs (with subs) across the long wall with superb results. As Ralph notes, they'd probably be fine on the short wall, too (given the response null to the side), but my room isn't laid out that way. Without the subs, bottom end response is too limited for my taste, but the room size is almost ideal for the speakers, IMO.

FWIW.