Pics of girlfriend?
If you decide to fly I hope the plane slowly disinigrates or crash lands in Juarez
Seriously, on such an grande adventure you'll need wheels and a Jeep isn't going to do.
Jeep TJ would stick out worse than a transvestite hooker at a stampede breakfast.
Ever try to get parts in South America ? Probably easier to get transvestite parts than jeep, not that there's anything wrong with that, just sayin...
Sell the jeeps and get into a Toyota. 4Runner has more space and is still quite common in south/central America.
Don't waste your money on gay tuffy products, instead do a 69000 point inspection on the yota and rebuild or replace everything you can while you have your own place & tools.
If you can, enter Mexico at the Mexicali border just before a big baja race, makes life much easier!
Smooth sailing from there as long as you have no guns or drugs.
Should also work on your tan before departing