I have gone down the road for the FJ with 3S, 4S and 6S. If you want speed, she will be heavy and she flies like a pig compared to a 3S set up. You can get 150 mph and then want to enjoy the smooth flying traits of this plane. If you want speed the first hurdle is the airframe. You need to push the FJ past 1KW to get to 150 mph. A hot set up is required. If you want something fast and yet manageable try to look at a 4S, 3,300 pack of 35C and a 28mm motor of around 3500+KV. An 80A is the bare minimum. Try to stick to a 90A or 120A ESC to keep it safe.

My new FJ will be a 3S 2,200 set up with a Mega 16/15/3 ... hehehee ... keeping it light to enjoy easy flying. Speed kills!