Those KHTs are going to be pretty bad, stay away from them. You are not budgeted well for a good sub and five good speakers. My advice is to get a good front pair and get a good sub. You might look at something like a Hsu 2.1 package with one of their 12" subs, and add more speakers later as your budget allows. You will want to keep your front three speakers consistent but it doesn't matter as much if the surround speakers match. You are going to need a powerful subwoofer because the room is pretty spacious.