Swaping to the Gen2 tail requires the Gen2 subframe. It also requires the relocation of the rectifier which is located in the tail section of the Gen1 and near the belly of the Gen2. Also, you will have less storage space in the Gen2 tail. There are a couple of threads detailing the swap at
www.hayabusa.org
I personally prefer the Gen1 tail with some modification. Here's mine: