okie... first things first, as far as how much whp the car's gonna throw down depends on what type of internal work he has done. As long as this person is somewhat intelligent they will only be boosting serious lbs if they have some decent internal work done to the block. If he's running stock internals don't expect him to run much more the 9 lbs unless he has no regards for the impact on his motor. Now if he has some time thrown into the block like new pistons, rings, rods, titanium sleeves, etc. then expect to see some higher lbs of boost been pushed. If he's running 15 lbs or more he'll give you a run for your money cause a civ clearly weighs less then a cobra. As far as tranny goes he's gonna wanna have the GSR tranny to match the GSR motor. Stock the B18C1 pushes 170 to the flywheel so figure 145 or so the wheels. Strap a T04 turbo to it and run 12 or 13 lbs, some internal work and some other extras on it you'll see whp in the 300's easily. Not sure what the powerband is on the cobra but a B18C1 with a T04 powerband is definately gonna be stronger on the higher end cause once that turbo spools up to full potential... seeeeeyaaaaaaa....
I know I didn't answer everything but hopefully this will help ya out a little.