First of all, if you are talking 2013, I think you are SOL as to departing on 10/22 as it's 10/27. You may have already missed that flight.
However, I think DL metal is your only option? Maybe Aerolineas Argentinas or Aeromexico (through MEX)? I don't think those will either improve your experience nor your possibilities for upgrade, though. Plus, Aeromexico in FC/BE in my experience is not any better than domestic FC in the US as far as the seats go.
Looks like you can go through ATL or DTW on DL.
As to SWUs and availability, I don't think anyone but Delta can tell you that anymore, as they removed that ability from ExpertFlyer a week or two ago. You'll have to call and ask.