no matey you dont NEED an aftermarket boost controller, just bypass the amal valve and run the actuator `direct`, this way the boost is controlled by the the throttle. the mapping for the fuel with TUNA will be fine with the boost upto 22psi. its personal preference if you want an aftermarket boost controller.

the standard cooling system is ok for that power, there is a little mod that doesnt cost a penny that you can do to help that brings intake temps down a few degrees .

its up to personal preference if you want to uprate the pre rad or go air to air, every little helps but it isnt needed, theres a couple of lads running near 400 with the standard setup so its cool enough, but id say thats probably its limit.

ap racing organic clutch will be ok with that lot, thats the one up from the standard clutch they come with.

the standard clutch has been known to take 300bhp+ so i wouldnt bother changing it until you find the limit of yours

just make sure you get the boost setting on your actuator checked and setup, get it rolling roaded just do double check your fueling and make sure the chargecooler pump is running.