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.  

audiotroy, to be kind you have no idea what you are talking about and judging by your dialect would not know a good speaker if it hit you over the head. Your explanations of physics and acoustics lack any semblance of reality and the way you describe auditory phenomena suggests you can't hear either. 

Oh, Martin Logans do not image any better than any other ESL or Ribbon loudspeaker. They are compromised by having to cross to a woofer usually at 250 Hz or above because the curved panel is non linear. Sanders, who designed this panel for ML abandoned it as inferior which you can read about on his web site sanderssoundsystems.com. 
As for size it all depends where you like sitting. I like being up front in the first 10 rows of a big concert and at the stage in a small venue. Point source speakers put you in the back of the hall. If you increase the volume to try and get yourself up front you get a very surreal effect of a band playing very loud at a distance. 

Audiotroy, when you go to a large say stadium show what you see are very large usually JBL linear arrays. They are in no way point source because point source loudspeakers suck in that application for the same reason they suck in large rooms. Now, you can do the same thing with dynamic drivers such a the Near Field Pipe Dreams or the Carver Ultimate Line source. I have heard the Pipe Dreams and although capable of huge volume they could not image. I have not heard the Carvers. There are applications where point source speakers are the way to go. But as I said before Unless you want to sit right on top of the speakers this is not one of them. All this is in Loudspeakers for Dummies. I suggest you read it. As I said before, Maggie 20.7s are the perfect speaker for this gentleman. They fit all of his requirements, will do 95 dB in this situation and image much better than and point source speaker. The only reason I would not recommend is if he liked listening to very loud rock and it does not seem that he does. Another issue is that as background music throughout the room the Maggies and any other linear source dipole is going to sound more natural, less strained, larger and more powerful. It would not be unusual with some special recordings to think there was an actual person across the room singing. That will never happen with a point source in tha application. Palidin, I encourage you to find a dealer and listen to these if you can and have a look at them. They are also really quite elegant and make a great conversation piece. 
There are some people on this forum that spew off mindlessly without knowledge or experience. Taking their word for anything is dangerous and very expensive.

Audiotroy, Most audio sales people I have known, and I was one once, were rather poorly educated, impressionable, dishonest, mythologists whose sole purpose was to sell whatever stuff they had in stock that had the largest profit margin. It was so disgusting that I quit and created my own consultant business designing and installing systems for people in Coral Gables just south of Miami. It was based solely on reputation and word of mouth. I had a blast.
rbach, there are many issues in Hi Fi that are strictly a matter of taste such as a preference for tube or SS electronics. Some issues are a mater of experience like what speaker will go best in what room. But there are issues that are a mater of well known and proven science which are frequently overlooked to other's detriment. Not good. Again I refer everyone to John Eargle's Loudspeaker Handbook. There is a lot of math in there but his explanations are wonderful and he covers everything. It is a great reference to have and I think every serious audiophile should read it and it is OK to skip the math parts:)

Gee this is fun. I will now respectfully bow out. I encourage everyone with interest to read respected manuals on the subject of speakers and all their associated parts such as my favorite, The Loudspeaker Handbook by John eargle. There are several such books but this one is easier for simpletons like me to read and understand. 
paliden, good luck with your search. Do let us know what you decide to do.
stfoth, thanx for the reminder. I was thrown up on yet again today by a young lady who suffered food poisoning. Goes with the territory. 
cleeds, most of my experience with audio sales people is back in Miami, Fl 1980. My relationship with those I respected was on the level of personal friend. But I can tell you from audiotroy's behavior that he is more typical of the types I knew in Miami. The difference is that I do not sell anybody anything. I have nothing to gain or lose. I am sure Audiotroy is as nice as they come as long as he thinks he might sell you something. Make no mistake. He is here fishing for customers. If you do not believe that you are naive beyond anyone's help. My own mantra is, never trust a human who is trying to sell you something. Humans are far to dangerous. Rock and Roll! 

Mike