Thats a good start mate, if you are aiming for full throttle for a prolonged length of time i would invest in a good oil cooler, perhaps a baffled sump for the twisty bits and the mother of all intercoolers to keep your charge temps down. Don't run silly boost and you should be onto a fun car. Have a chat with a few people on here as quite a few have build escort rst's just for the track.

Good luck

Rob,