Hey Walldiver, welcome. First things first...have you gone out and listened to any? That'll be the first thing everyone asks/tells you to do. If not, you owe it to yourself. If you're going to invest the cash, take the time, drive around to a handful of places, equipped with material you listen to/watch often and know well, and just listen. It's part of the fun.
That aside, are you looking for a 5.1 or 7.1 set up? Are you opposed to internet direct brands? If you do opt for a sub, do you want the price of the sub to be included in your $1K limit (that'll be challenging), or would there be a separate budget for that?
And yes, it's time to replace those speakers.

You're off to a good start with the 2807. That's an awesome unit.