robshaw
I have no experience with the Mon or Marten Oscar speakers, and wouldn't recommend the Devore for rock. Of the speakers that you listed, and considering the relatively small size of your room:
I love the Arendal 1528 bookshelf $5,200 and 1528 monitor $6,800 for all types of music, and they are on my short list for my next set of speakers. Pay attention that the 1528 monitors weigh in at 100 pounds each, so you'll need their stands at $1,500 a pair.
Acora speakers too are great, but I don't like the ceramic drivers in the MRB-1 or MRC-1.......they can be unforgiving on poor recordings. The next step up QRBs are much more to my liking, and too are on my short list.
If I may be so bold, I'd suggest you speak with Greg Roberts at Volti to schedule a listening session for his speakers......which he'll set up at his factory. He's a tremendous gentleman, and the Voltis might just fit your needs. He's in Baxter, TN which is about an hour and 15 minutes east of Nashville. His speakers too are on my short list, probably the Luceras.
When you go to Nashville, I'd check out HiFiBuys and see the Yamaha NS5000 speakers. Not a brand that typically comes to mind first, but man are they brilliant speakers.