dpends on the spec of the other cars, they will always have the advantage of 4wd, I had a series 1 rs turbo 10 years ago that had chip actuator exhaust and it could stay with standard cosworths that was supposed to have been producing 180bhp
a genuine 200bhp rs turbo will be a very quick rd car. the more power you have the more other things will suffer, ie you will need uprated clutch, brakes and so on
I see your from scotland, perhaps have a chat with the crew at sitech racing, I hear very good things about them. many people speak highly of them, tell them what you are looking to achieve and your budget etc
I can't wait to get mine fully converted to efi and back outta the garage in april, not driven it since rsoc national day in september and I miss the turbo kick already