1.8 cvh needs a bit of work and can be expensive the rs block could be used but uses low comp pistons so itll be slow and boggy go zvh use the 1.8 block there cheap as and fairly easy to do and youll end up with a better engine for less money or just put either a 1.8 or 2.0 zetec in out of a mondeo again its not rocket science and the rewards are there to be had.
cheers mike