so long as you're under factory warranty, best one you can get is ford's own Extended Service Plan.. do not deal with easycare warranties, they SUCK and frequently turn down warranty claims for no reason, where as ESP is just like the factory warranty but with a deductible.. If you are worried about your car that badly.. it could pay off, but be sure to have all maintenance records in case the engine blows..
Or you could befriend a ford mechanic.. and they'd usually give you a good deal on repairs when needed..