I recommend you take a look at
www.bluejeanscable.com
Not the least expensive, but not the most expensive either (by a long shot). Good quality and if you have issues, you can give them a call. They have excellent customer service from what I have heard.
I would (personally) recommend a HDMI -> HDMI cable, then use a HDMI -> DVI adapter on the end. It seems the push is for HDMI instead of DVI which means that a few years from now if you change out the projector, you will likely find it with a HDMI connector on it.
HDMI -> DVI adapters are not very expensive.