Not sure about the black top. For the early Zetec-E you'll have to modify your CVH engine mount. And iirc you'll need a gearbox with the starter mounted behind the engine. So RS-Turbo boxes are a no-go. But the bolt pattern gearbox <-> engine will be the same.
Zetec-E is a development based on the CVH, so this is why this ZVH thing is possible.
RS2k 16V is a development based on the Pinto, so totally different from the CVH and Zetec. Chain-driven camshafts. 2.0 16V, 150 bhp. Good standard engine, more hp than the 2.0 Zetec. But less tuning parts available.

But why do you want to spoil your RSi with a 16V engine? CVH MFI with red twin coils is the only way to go in an RSi!