If you need 6500 points, you would likely spend less money (and certainly less time) spending a little more money and getting your tickets in the lowest class that gets 1 point for mile (note that is an important change for 2004)
Personally out of MIA I would fly to Europe on an M class fare, gets your PLT challenge, plus 5k bonus miles for EUR04, plus double miles for the second leg (ie the leg on which you complete the PLT challenge), plus gets you qualified for FLY04 challenge.