My website uses 2 columns, but the only way I\'ve been able to get the columns height to match is to use a fixed height, but this presents a \"scrollbar in a scrollbar\" iss
The other solutions look a bit too complicated to me. How about this:
Set both of your columns to transparent background and make a container for both of them with the desired background as alpha-transparent png.
Maybe not the "cleanest" solution, but definitely a simple one. Looking at the website you linked, that's what I'd go with.