Blacktop sumps are suitable for mating to a type 9, there is small mod to some of the ribs on the side for clearance but apart from that nothing else.
Escort 1.8 silvertop is the way to go, pre Aug 95 and you don't need a cat. Problem with using a newer engine is the emmision targets, the newer they are the tighter and they are on the log book so you need to satisfy them at every MOT.
Pre 95 is the slackest, apart from a Q plate which is just a visible smoke test. That way you can use as new an engine as you like.