What about having an "alt" like text popup for the names that are truncated? In this case all of them, since you wont hover above the ones you know very long. Keep the same width as is, and just have little text baloons pop up for any that you aren't clear on and have to hover over a bit.
Having a width scroll bar just takes away from the vertical screen space and is very unatractive IMO.
-- Robi