Hi Adam, welcome to the forum!
An attempt to answer your questions:
1.
Are the stories different in the black and white versions? How much do they change?The stories are virtually the same, almost frame for frame, but there are a few sequences and frames cut out from several of the b/w versions to make the colour editions fit 62 pages.
The b/w versions of
Congo, America and
Cigars are in Hergé's earlier style, a bit similar to
Soviets (the colour versions were completely redrawn).
From
The Blue Lotus up to
Crab Hergé used the b/w edition for the basis of the colour books, but added some more embellishment, like more detail in the backgrounds.
At the moment there are no English b/w books post
Lotus (chronologically speaking), but you can get them all in French and some other languages.
2.
On one of the forums it was suggested that there is more than one chronology to the books - is this true? And if so, what is the correct order to the books?Here's a link to our
page on Tintinologist which has the order they were written in, which is generally speaking the correct order. The page also has the dates in which they were first released in English, which is different.
I think it is this to which you're referring when you say 'more than one chronology'. Because the order in which they were released in English began as fairly haphazard (for a number of reasons), the translators altered the text of the original French in some sections where characters that were previously introduced in another book were referred to, and vice-versa. It's a can of worms.
3.
Which versions of the books do people prefer? And which would you recommend if I had to choose between the two versions?I'd say it's worth having a few b/w white books alongside the colour editions as they are significantly different in 'feel' to the colour editions and in a larger frame format. The pacing is also better in some of the b/w books because it's spread over about 130 pages, whereas the colour versions are all 62 pages. I would especially recommend
The Blue Lotus and some of the other later ones (when they get to do them in English), like
The Broken Ear, but that's just my personal preference.
I hope that helps a little.