Speakers help for a newb...

I would suggest a pair of Magnepan MG12's. These can handle from rock to Classical and all in between. They are clean, pretty accurate but some may need a subwoofer to go with them and some not. You can usually find them here for around $650 to $800. Get the SN's and call Magnepan to see how old they are. Not to see if there are under warranty but some of the current Magnepan models have been on the market over 5 years. Not that it's a problem but My limit (knowingly is about 3 years or so).

Try and avoid speakers with foam surrounds especially if you live in a humid environment and if the speaker sat in in direct sunlight. Both cause foam surrounds to fail quicker. Take the same precautions with the maggies and keep them out of direct sunlight.
It is a very well balanced speaker and it's hard to beat at the used price.

Or opt for a pair of MMG's and a very good subwoofer like a Hsu and there are many others that are good and fit into your budget. The MMG's are smaller and produce less bass. The rest of the spectrum could be in the same ball park.

Good Luck and Happy Listening.

The previous responders are correct with the Vandersteens.
You will NOT need a subwoofer. Your room should be large enough not to have bass bloat as I did in my 14'x13' room.
But your room isn't that much larger so try and find a friend that has some Vandersteens that you can borrow. The Maggies still have IMO better mids and more open mids than the Vandersteen. It's all a matter of opinion you know. The top end is pretty close and the bass in smaller rooms to me is much better with the Maggies and Bass bloat is not usally a big problem. The problem the gentleman mentions about the quasi ribbon I would call Magnepan to verify that.
I know several Maggie owners and none of them have had those problems over a 10 year period. Direct sunlight is a problem for any speaker that is a planar, electrostatic or dynamic with foam surrounds. But when you speak of balance and especially if you like listening to classical, jazz, and many other types of music Maggies will impress you. My listening room was too small to accomodate my MG12's and I ended up with a pair of Spica TC60's which are still there 1 year later. But... I still remember and miss the Magnepan MG12's. They gave a bigger
sound. You will experience the same thing with the Vandersteens but make sure you get the Sound Anchor stands and put the heaviest material in them and that will help also. Vandersteen also makes some filters to help you control the amount of bass that enters your room. Check into that if you choose to go in that direction.