Todd, welcome. Lots of details, but my first impression is that for that room volume and to fit your budget, the M60s plus EP500 would be better overall.
Your present arrangement has the mains separated by 5' or less and you're sitting about 12' away. If possible it would be desirable to have the two distances about equal. Would it be acceptable to rotate everything(except the sub) ninety degrees clockwise and have the mains separated about 8-9' at the edges of the big window with the seating being about 8-9' away?
If you're getting a 1080 set, such as the Sony LCoS, which has good scaling, the scaling of the player wouldn't be used and something could be saved there.
No problem with the 2807(note that the new 2808 is due in about 2-3 months)if the features suit you.
Considering shipping costs, wire for the speakers may be most economical at a local source such as Home Depot or Lowes. Connecting cables at a reasonable price and which do the job as well as anything else are available at online sources such as MonoPrice.
