Barichello was apparently their first choice - they even had initial talks with him. He prefers to be number 2 at Ferrari, though, and has signed on 'til 2006. Ferrari will be lucky to ever find another driver who's quite so ... "accommodating". After him, I think Button is their next choice, then Webber. Webber has some political, and probably financial, baggage courtesy of his relationship with Flavour Flav, plus Button is already familiar to the Williams guys. He's was less irritatingly chirpy/flirty in 2003 than in previous seasons too
For both of them, though, a lot depends on how their current teams perform this year. If Button still can't get on the podium, he'll be talking to Williams by mid-year. If Jaguar fall back into their old ways of mediocrity and disappointment, Webber will be looking at Renault and maybe Williams.