128 will give you great views of the West end zone.
I sat here on November 13th, 2011 vs. the Buffalo Bills; row 8. We were close to the field and also behind the Bills sideline. There were a decent amount of Bills fans that were congregating in the area. You'll have plenty of opportunities to snap photos of the visiting team.

The best thing about the lower level is that you have to look up at the jumbo screen to notice it. When you sit in the 400s or the mezzanine, you can't avoid looking at it after every single player. It lights up the entire arena and has crystal clear display but I actually think it hinders this stadium.

You're going to want to enter gate K to get to this section the quickest. No sense in entering the stadium on the East side and battling the crowds to get to the West side.

I have found the best outlet for Cowboys tickets to be Stubhub. You can choose where you want to sit. When you buy from ticket scalpers on the street, you have to buy what they have and don't always have enough time to study those seats before you purchase them.