I had to do some research on XLR cables recently as I'm going the balance route too.

I second Gonk's recommendation of Blue Jeans and monoprice. I used both and they are great.

The best bang for the buck I found for XLR cables is from markertek. I purchased their "premium canare XLR" line. They have the same specs as the Blue Jean Canare L-4E6S Star Quad, but at a lower price.

No affiliations, just a happy customer from all three sites.

DMX