Anyone for S.F. -> Baja Mexico?

[neverwrite]

I am planning to ride down the coast to Transpeninsular highway and spend some time in Mexico.  I plan to camp and cook along the way, and go fast, cheap and light.  I am looking for travel companions leaving between late July and mid August.  I have some experience with touring, but none with Mexico and would appreciate tips from those who have gone before.  I am nervous about the back roads on a skinny-tire-drop-bar touring bike.  Will 700x35c Paselas be adequate if I leave the highway?  Should I drill my rims out or will I be able to find presta tubes south of the border?  
Thanks,
  James