RE: Best Bang for about 700 bucks
You're going to get a lot of responses here but I'll start it off with either the TT Mini Titan w/ DX7 or the Trex 450SA w/ DX7. If you could stretch it a bit further I'd say Hurricane 550 w/ DX7 (not the micro set w/ 285 servos but the 821 servos).
The Hurricane kit is $320 w/ motor and esc, add a GY401 for $140 and DX7 for $350, too bad it's $100 over what you're looking for.