In your example text, the word except
is used as a conjunction and it could be replaced by the conjunction only
— as you suggest — with very little change in meaning. The difference is nuanced and a matter of preference. So it is your choice:
"Picture James Bond, except without the British Accent."
OR
"Picture James Bond, only without the British Accent."
Your second question, about and
/ or
is harder to answer. Because the two words have very different meanings (as noted by Crosscounter), it is usually easy to decide between them: do I want both (cookies and milk) or do I want one (cookies or milk)?
In the text you are examining, there is nothing so concrete to guide us, since I am without the items described. This may be another matter of preference, but I have a strong feeling that or
is better. I cannot find a rule to support my preference, but here's my logic:
In English usage, there are word pairs that belong together, called correlatives. These include both—and / either—or / neither—nor. It seems to me if you use and
you imply the word both
, and if you use the word or
you imply the word either
. When I ask myself if it should be "without either a British accent or a six-pack" or "without both a British accent and a six-pack", the word either
emerges the clear winner.
So, with the understanding that my logic may be flawed, and this may actually be a matter of preference, the word or
is preferred:
"Picture James Bond, except without the British accent. Or the six-pack"
NOT
"Picture James Bond, except without the British accent. And the six-pack"