no reason you couldn't fit the zvh engine in the rs2k, they do have a habbit of breaking props/diffs IIRC.
engine will marry up to the mtx75box, it's a stronger box than the bc/ib5 ones also.

the standard I4 engine in the rs2k produces 150bhp, tuning wise will cost quite a bit, not a very popular developed engine really, cvh/zetecs are more common.