Versatile, non-fatiguing speakers for a small room under $1500 used or new: advice needed!

Hi, first post here! And not a very original one, my apologies!:)

So after years of listening to music through miscellaneous mid-fi solutions, I am finally thinking about dipping my toes in hi-fi audio and putting together a dedicated stereo setup. Currently I am looking at speakers, and my head is already aching from the abundance of options, so I am looking for suggestions from you guys, primarily from those of you who have had first-hand experience building a stereo in a small room like mine and achieved results they are happy with.

My room is pretty small (approx. 13’ x 10’), and I will be placing my speakers along the long wall. My listening position will be 6 feet away, give or take; plus the speakers will have to sit fairly close to the front wall. 15 inches from the back of the speaker would be nice, but if needed, I definitely I could move them out farther into the room (up to 20 inches from the back of the speaker), for listening sessions and then move them back again. There are several rows of shelves , filled with CDs and stuff, in the middle of the back wall above my head (not wall-to-wall though) - would that work as dispersion? I’m thinking of applying some room treatment behind the speakers, and on the right-hand side wall as well (if needed) - on the left hand side is a window covered with thick curtains.

Budget: under $1500 used or new.
I listen to all kinds of music, primarily rock of all eras and subgenres (blues/folk/prog/hard/art/psych/indie, etc), jazz, blues, classical, acoustic, singer-songwriters, female vocal, 80s new wave/post punk, some heavy metal. So the speakers need to be as versatile as possible. As someone who likes rock music, the bass is important, but I live in an apartment (neighbors!), so I have to find the right balance there as I don’t want to overload the room - the bass has to be there but under control and not boomy. I want as big a sound as possible in my small room without overpowering it. In general, I’m looking for engaging, non-fatiguing, dynamic sound with good midrange and tone, with enough punch to rock out when needed, nuance to play softer, more sparse types of music, and resolution so the details in fast complex passages don’t get lost or smeared. Not a fan of excessive brightness, sibilance, or harshness in the upper midrange.

I’m primarily looking at standmounts, but maybe certain smaller floorstanders would be fine? I’ve seen opinions claiming floorstanders are the way to go, regardless of the size of the room. What do you think would be preferable in my situation - apartment with neighbors, 13’x10’ room, long wall positioning, distance to speakers about 6 feet, maybe less?

I have a pair of Vienna Acoustics beethovens that are smooth and will take the edge off old rock recordings played thru affordable electronics and will sound pretty good up to95 db peaks and sound really good at average levels. Bass is surprising for their size and the tweeter is better than average. Theres always the cerwyn Vega 215’s 
i've had good luck with a pair of thiel cs.5 minitowers. very small footprint. solid and adequate bass down to 30 cycles or below. they need their power though, no less than 100 watts per side of clean power, they are a 4 ohm speaker. i haven't heard anything more neutral and anything which images better than these speakers. they are available used for not too dear compared to how much they were when new. they are MELLOW above all, totally unlike their larger brothers which are on the hard side of neutral on all but the cleanest material. 
I've seen two pairs of Legacy Signature IIIs go for under $1500 (and mine cost $1600 10+ years ago).  They are extremely easy to power, have huge dynamics and deep, tight bass.  They also have a rear ambience retrieval tweeter.  They have driver adjustments too!   A bargain for a speaker that can do it all.  
A brand which receives universal acclaim are the Von Schweikerts.  They can be purchased used as older models which fit your needs for under $1500, often under $1000 and are relatively small at that price.
Plenty of choices, Harbeths p3ser are very very nice, dynaudio special 40