Europe got the 3SGE like Japan but had a few differences. 2.0 litre. The UK however also got the 3SFE in one of the early models which is a 2.0litre but has the F head like the 5SFE. Less power but it still got the bakes the 91 Turbo got unlike the 5S that got single pot fronts.What engine did you get in your NA cars over there? Do you/can you post a photo of the engine bay?
I'd say that if it's like the 5FSE (or is it SFE....whatever), I wouldnt bother with intake an exhaust unless it's purely for making noise, it wont make much of a real difference. You'll drop a grand on three items and pick up 5hp or something