I agree with you on your thoughts regarding monitors (bookshelves). I also have a smaller room and though my budget is now greater than yours, it wasn’t always so. I still use monitors and am considering implementing subs. Quality bass costs! As an aside, there is a Cambridge Audio 640a for sale on AG for $230 to include shipping. Seems like a great deal. I think it would serve well given your budget and allow for the dollars you wish to spend on speakers. You would need a separate DAC however. To me that is no big deal, within a $1500 budget there are many, new and used, that would fit.
Regarding speakers, I remain in belief that my suggestion that you might purchase an amplifier, DAC and other source components that are fitting to a $1500 system and a modest pair of speakers allowing you to enjoy your system while exploring the speaker market. You could take your amplifier when auditioning speakers.
My recommendations in no way are intended to degrade the other fine opinions offered. Just many ways to an end. Enjoy the journey.