If your not wanting to do deep tillage I think the McFarlane Reel Disk looks like the tillage tool for working corn stalks.  This picture is off their website and is after one pass in the fall in standing stalks but I bet with a second pass in the spring it would leave a very good seedbed while still only working the top couple of inches. 

The McFarlane is a new tool so it's not going to be cheap.  A cheaper route would be to make one pass in the fall with your disk and follow it in the spring with a JD 550 Mulch Master, I think  you could pull a 12' 550 ok and they work really good in heavy corn stalks.