If I'm understanding correctly, you want to make the entries part wider?

This is the code to change:

.layout-two-column-left #container {
	width: 800px;
	}

Make the width 900px instead, and then also change this:

.layout-two-column-left #beta {
width: 600px;
float: right;
}

Make the width of the beta container 700px. The side bar is 200px, so that plus the content needs to add up to your total content width.

Also, the header won't line up perfectly at the top anymore because it's only 800px wide. You can change that also or leave it. It shouldn't be that noticeable because of the background tiles.