Looking for a good full range floor stander

I'll assume the system will be going on the 20 foot wall. An omnidirectional point source speaker will make a room like that sound like a giant cavern without very significant room treatment. The end result will be that the speaker will get lost in the echos. Keeping the listening position as close in as you can will help. The ultimate speaker for a room like that would be the SoundLabs 945. Unfortunately it will not make it up to a 12 foot ceiling so it will stop behaving as a line source at about 110 Hz. Ideally you would cross over to a subwoofer array there. This all goes way outside your budget but the point is that a line source dipole will project better into a larger room and limit reflections off the floor, ceiling and side walls. This will give you less echo and a better sense of the the stage and image in front of you and it would give you a little more leeway in regards to the listening position. 
The Magnepan 20.7 is in your price range and is a dipole line source down to 150 Hz. It will play the type of music you like effortlessly and if you felt you needed more bass subwoofers could be a future option. They will not play as loud a horns or a large point source so if you were a Metallica fan I would have a hard time recommending them in that room. Otherwise they will sound much more realistic, project better into the room and suffer less from room anomalies than other types of loudspeakers. The next step up is the 30.7 if you happen to find some cash hidden in the Mattress.  

Mjstoyn most large panels suck. Try an image that is out of focus, the large flat diaphram causes diffraction which gives you a very large unfocused soundstage as both your midrange and top end freq are bouncing off the diaphragm.

Add in poor bass your back wave is cancelling out your front wave which leads to no impact. Even with subs not realistic sounding.

Then add in low efficiency and compression when played loud. 

A large poïnt source with room correction does work in a large room.

Go to a live music show ever see a giant set of panels?

Big room you need big dynamic loudspeakers

Other speakers might control the room better, but for getting lost in the musical pleasure, my money would certainly go for a pair of Wilson Audio Sabrinas. Those are not for GAS people, but for those who truly love music!

Mtdining, the Sabrina are excellent loudpeakers that are not designed for this size room. 

You would need a set of Daw or Alexias to provide enough air movement for this size room.

Large room = high efficiency, high spl, deep bass, physically larger loudspeakers.

It is really that simple, for this reason we recommend speakers like the Legacy Focus, Focus XD with Wavelet, or the Aeris they will fill up a large room beautifully, are they the best speakers in the price range that is a different question, they are really great sounding loudspeakers for the money that will work acoustically in the OP's very large space.

Add in the fact that the OP can go perhaps to a Legacy dealer in his state and listen to the speakers or here them at shows is a bonus.

Dave and Troy
Audio Doctor NJ Legacy dealers

@milpai 

I agree with you that the Proac D48 would be a great choice.  I had a pair of D30r's (the D48's sounded great but were too big for my room) powered by a Bryston 14b cube amp and the sound was fantastic.  At the time I was thinking about the Legacy line but thought the Proac's were much more musical and way better looking.  Hope this helps.