Those cooper ss are nice cars and the works pack should be nice for em (but expensive at 4k!!).
We had one at one of our last meets, nice looking car, good interior etc (and nice to know that BMW has sorted out most of the problems with them now ) but id be careful about racing much in them, and big power will come at a cost for you
The Focus RS is an unknown quantity except its going to have around 212bhp and more than enough torque to go with it (250lbs?) and will ford bring out an enhancement pack for it too?? You never know as those 1.8ltr engines are quite tuneable (its also been quoted as having the best chassis in its class!)
WRXs with their 215bhp are still quick, heavy with it though but that helps in the handling department along with the performance pack you can purchase them for (and then people decat them, all 3 cats off!) so it gives a little more power So if you meet one that doesnt have the standard back box on i wouldnt try it on as with cheap mods these can be rather seriously quick cars!
Brakes.... id get yours upgraded if i were you, 2 pots are ok but if your going big power id go big brakes first
Big power.....
Big power in a light car (what do they weigh in at? 1050kg?) gives you big problems
I think that most people will tell you that torque steer on fwd cars is a pain, it slows you down and gives you less grip as the front end struggles to get power down can be solved with an LSD but they will cost you about 1k inc fitting.
Enjoy it thou they are nice motors but it may take you some time to get use to its limits, especially in the wet!
Tony