Thanks for the replies, guys ...
Doing a lot more reading and taking advice from some other sources, I gather the multi-point ECU controlled system will be fine for our 1992 LPT (and for my friend's 9000 CSE). I think a single-point analogue system will be fine for my CIS/K-Jet car and I am just waiting on a reply with pictures from a Hungarian online friend who has this setup on his two CIS/K-Jet cars.
I have also found a company in the UK who will offer interest free credit to get the system installed (and you use the savings to pay for the installation over time), which will help my friend out. They do not offer a system that is compatible with my CIS/K-Jet car, so I need to do some more reading there. John McKenzie's post has given me a lot to think about - thanks fella!