Welcome back! First off, what you like the sound of is extremely subjective, so it’s imperative to buy what YOU like. Secondly, placement is critical for any good speaker, so don’t worry about it being a concern for the Maggies. Thirdly, the quality of the amp is more important (IMHO) than the rated specs. A good 50 watt hi-fi amp should be capable of driving just about any speaker to reasonable volume, but no harm in going with a similar quality higher powered amp....you’re more likely to cause damage with an underpowered amp.
While you may not have completely ruled out traditional box speakers like the JBL or Klipsch, it sounds to me like you have a preference for the planar speakers or non-traditional enclosures that address the internal contribution of the box, so why not focus your energy on those types. It's worth noting that the JBL and Klipsch are both capable of ear splitting volumes, in case you like to play very loud, but since you seem to like the Maggies, that may not be a concern. Some of the names you mentioned are excellent....Harbeth, Vandersteen, Tekton....Totem, Sonus Faber, Focal, Wharfedale, are a few others. Enjoy the journey, and best of luck!