2000 GT 4.6 swap to 351W

I have thought of supercharging my GT,but I decided to upgrade to 5.8. I am new at engine swaps and mods. I now it will fit with motor mounts. My question is what headers, rods, cams and other intake mods do i need to get more out of the engine I have (which is stock 351w). I am looking to get around 400-450 or a little more without supercharging or turbo. And no NOS.
Also my car's tranny is auto and I am asking which tranny would be good auto or manual. plan to put 3.73 gears for street and have 4.10 when I race it. Have gears already. 351w would snap my car in half with my stock tranny with 3.73 or 4.10 right. any info or book on swap would be greatful.
Sgt Crouse, Gregory
Air Assault