Get some logitech speakers for a good price. They are only like $50 along with your monitor. You cant seriously think that built-in speakers are anywhere near any decent speaker system.
i would go with the hanns g (out of your list, if u just said whats a good 19 inch monitor i would have said the 206bw, 1 inch bigger), a friend has had one for years and never had a problem. how can u not tell the difference from 2.0 and 5.1, i can tell the diff from 5.1 and 7.1-