It is much more involved than that, and requires more parts than what you have listed. You are going to need a crossmember, a torque arm that bolts to the chasis, a driveshaft, speedo parts, tranny lines, torque converter, shifter, oil cooler, and of course a tune.
Unless you are going to be putting down over 400ft lbs of torque, it would be a waste of money and time. The stock 4L60E can handle that and a little more and would be cheaper and easier in the long run. The transmission you have is over 11 years old and was probably beat the hell out of, you would be amazed what a refreshed transmission will do.