If you are going to use that 120 I would recommend the Hellcat. You will need to purchase retracts for the Hellcat if you do not want to use the supplied fixed gear. The 120 in the P-40 would require a lot of tail weight. They both fly really well. Here is a picture of my Hellcat. I was waiting for the retracts to arrive. I installed Sierra Percision retracts and they are awesome. This Hellcat flies really nice. The span is about 10" bigger than the P-40 and will weigh about three to four pounds more. I am using a YS 120 in the Hellcat which is a perfect match for this plane.