You are getting very good advice from the posters, here.
Our great room is roughly 1/2 the size of yours and I struggled to find a good audio fit. Do not expect dynamite performance in a room that size with two mains and a subwoofer. However, getting a 7.1 or .2 or .3 setup eventually will help you distribute your music much more generously and evenly. Unfortunately, I cannot see your room drawing, so I can't make placement suggestions.
If 2 grand is your budget for getting started, it's doable, but diminishes the overall quality potential of your final 7.x system.
I don't necessarily agree with a couple of the speaker choices recommended to you, especially the Klipsch. They are indeed very efficient speakers, but are also the brightest and harshest of the bunch thus far suggested. None of them have the warmth or smoothness you crave. It's unfortunate that you can't audition speakers...they are VERY subjective when it comes to personal preference. A suggestion I would make is the attractive ERA Design line (signalpathint.com), particularly the D14/LCR4/D4 series. They're voiced by (Aerial Acoustics guru) Michael Kelly and reportedly have much the same, warm presentation as AA loudspeakers...at a fraction of the cost.
My strongest recommendation to you is for you to NOT scrimp on a subwoofer. Get the best you can afford. A good sub can make or break a sound system...both musically and for movies.
If you could boost you budget up a bit (easy for me to say, eh?!), you could get a pretty nice setup and prepare you well for the later full setup.
$800 - full featured and adequate receiver (Yamaha, Onkyo, Denon)
$700 - Hsu VTF3-Mk3 subwoofer
$1,000 - ERA Design 4 LCR pair
$250 - all-metal speaker stands from racksandstands.com
(Of course these can be had more cheaply from a used equipment market such as Audiogon.)
When you can afford to upgrade to fill out the system, my next suggestion would be to get a pair of ERA D14 floorstanders, relegating the LCR's to side surround duty and adding a third D4 LCR for center channel work. Then add a second sub.
Then let the upgrade bug bite you like it did all of us.
Good luck in your search.