I've got a 428SCJ that came with a C6 automatic. I changed to a top loader and went with an aluminum flywheel which I had match balanced to the flex plate I took off. The flywheel was nothing special, just a "standard" FE part. It cost me $200 to balance, and they did have to add some weights, but it worked just fine.
I can rent you the 10 year old for the install if you like, he's got SCJ experience!
Jon