Well, I did a quick daytime recon of the East St. Louis section (Front St., as I said in the OP). The train tracks and stuff. I actually didn't like the vantage point because there was like a big long walkway for a shipping company in the river that gets in the way of the view. That and the place didn't look too nice, there were a ton of bugs, and everything that I own is in the car for my trip to Phoenix.
The walkway would have been the best vantage point, but it had no trespassing signs at the entrance, and no one to ask to see if it was ok to go.
I ended up taking the picture from the bridge... it's to the south of the Martin Luther King bridge? So the arch was on the left an the city was on the right. Not the best shot though because the arch was dark. I thought that it would have been lighted better...