IF you musth have replica, buy one thats done, cost a fortune to make a decent one and they never fetch much cash finished.

Why would you want an RST engine in it though?

Why not have a RS2000 engine and then do something with that, like supercharge it or turbo it or put it on throttle bodies or something, at least its a 2.0 16v engine thats probably in good nick anyway, any cheap RST engine you get hold of will probably end up costing you thousands to get rebuilt corectly and up to a decent power.

Personally i would much sooner have a basic 2wd saph though, i really cant stand replicas (i know mine doesnt have a cossie logbook but its hardly the same thing as driving the wrong set of wheels and not having any of the other bits) to me if it looks like an escos and then doesnt go or handle like one its just a bit embarassing really.