not sure about the 1.8 to be honest.
as for the throttle bodies, you can use ones off a bike with cheap aftermarket ecu of some kind if you really want to avoid the carbs (mine are weber 45dcoes) .. not sure if he posts on here but rchambers on turbosport.co.uk got his mk2 running using bike TBs. Alternatively Jenvey or similar would be able to supply suitable trottle bodies, possibly a smaller size (42mm?) as they're more efficient than carbs. ECU could be more expensive with thre TBs though as obviously it then has to control injectors, but just ignition only.
I don't think it's relevant in your case, but apparently the MOT emissions test is done according to whatever's older - the enigne or the car.. so my mk2 will be tested according to 1980 levels despite running a zetec engine.

HTH