From that list:
I think Anthony Stewart Head would be fab. I don't even really know why, he just would, so there!
John Cleese - I think he is too much of his own big personality to really be an effective DW. It would be hard not to see him as John CLeese.
Joanna Lumley - lol, I think she could pull it off, but I can't really see it happening.
Sean Bean - I like this guy, but NO WAY could he be the Doctor, he has charisma, but its the hard-man-don't-mess-with-me kinda charisma, and I can't see it working well for DW
Roan Atkinson - NO! Was he a comic relief Dr Who at some point? Or was that Stephen Fry?
John Rhys Jones would be great! I love watching him ham in up in old Sliders re-runs!
What about, as a younger candidate, Hornblower, you know Ioan Gruff-something?