Ahhh yeah. Sorry, they were really screamy until the last CD, which was called "The Crusade". I should have clarified on that one. Listen to the song "Anthem (We Are the Fire)" off of that one and you'll see what I mean.
As for In Flames, try the song "Dialogue with the Stars" off of the album "Whoracle". It's all instrumental, so you can get a feel for the guitars. Another good one off of that one is "Episode 666". Whoracle and the last album, "Come Clarity" are the two I like the most from them, and Come Clarity has some clean singing in there. You can download the mp3s from this one off of Amazon for .89 each unless you have another, more frugal download method.
Finally, for all clean singing and awesome guitars, try out these bands' albums:
(band) Dragonforce - (album) Inhuman Rampage
(band) Sonata Arctica - (album) Unia
(band) Nightwish - (album) Once
Let me know what you think! You can preview most of these on Amazon's site to get a taste without buying everything.