You say your budget is $1500. That's a mighty large room to fill - especially knowing you'll need a solid subwoofer for that space. If that floor is concrete, you'll have trouble with bass with a cheaper sub. I helped a friend in Dallas, TX install a system in a 3500 sq ft house with a room similar to yours - but had 20' ceilings straight up. He has a Denon 2803 driving a 7.1 Paradigm setup with a 12" Paradigm sub. I think he spent $2300+ on his speakers. His two fronts are towers with dual 8" woofers. It fills the room nicely, but everything is at ear level - all surrounds are on stands. If you go hanging speakers off the ceiling or walls, you'll have to aim them at your listening position very carefully. Good choice on the receiver - HK's are softer - something you'll need in a big "echo" room like that. Look for a speaker setup with a high efficienty rating, say over 94db. Axiom's rate their speakers in two db ratings - I'm not sure of the difference. Were you thinking of the Grandmaster 500 setup? They make some of the nicest looking set ups. The sub in that setup is 70lbs - pretty massive. It should be fine.