i like the UK DC2 way more because of the front bumper mostly gives the car a mean look :P but as you say that the JDM is lighter (6) less Roadtax is always better :p but i am just guessing now that it would be able to put the UK DC2 bumper on it.
and the insurance here in the Netherlands are really unbelievable especially to the younger drivers since they need to pay more for that kind of stuff -_-. but i like the DC5 to but its just a tee bit to heavy and way to expensive for me (so far).
I found a UK DC2 here for around 8000 pounds. whilst that still is quitte expensive its a good car that you get then since its just breaking in a bit more most of them have only 50.000 miles on em.
and for tuning:
at my old school we have about twenty turbo kits and 3 superchargers so atleast on of them should fit :P and well i think its sporty enough in stock version but ones i get more money i will really be throwing in some simple tuning bits (better exhaust system, sphagetti outlet, better intake system and some handling stuff) no bodykits since i love its styling unless i can get my hands on the VIS cateye frontbumper