9A conversion with twin 40 Dellortos?

I Currently have a MK1 Swallowtail 1976 CL with a 2.0 3A engine that I am running on twin 40's.
I have just got a 9A 2.0 16v Passat engine and would like some info on setup of the ignition sytem, what sort of ecu do I need to run it off the original 9A dizzy?
Can I use the old Passat ecu or do I need to get another one?
What sort of a job is the conversion?
The 3A went in pretty easy, but I am just using a basic points type ignition setup.

Being from NZ - I'm unsure of the specifications of cars there. But I can answer in terms of UK spec cars and it should help.

9A uses KE-Jetronic and its rubbish! So its better to adapt K-Jet to the engine, eg use the fuel injection system from a 16V Golf GTI Mk2 or mix & match components, eg some from Mk1 GTI etc.

As far as ignition goes, the 9A's ignition timing is controlled by the management system you'll be junking, so also adapt/use the Mk2 Golf GTI 16V system. This isn't that complicated and is a small ECU which takes inputs of hall sender, coolant temp and manifold vacuum to set the timing. The dizzy is a 1/ignition event (4 slot) one, doesn't have any advance built in and is the same on the 9A and KR (the engine in the MK2 Golf 16V amongst others). Another component is the TCI module, this is common across many VW cars of the era, including the later Mk1 Golf GTIs.