Ok...

in terms of chasis there is no differences.

So the FD1 (vti/vti-l) are the 1.8 ltre civics (2006+) and the FD2 (sport) is the 2.0 ltr 2006+ civics.

The differences are the engine (and engine bay layout, so intakes and full exausts that fit one won't fit the other). Now the FD2R (the type r you refer to) is different again, the front (fenders panels to be exact) are slightly wider... so a genuine FD2R body kit or full replica won't fit our FD2 and FD1... and in case you didn't know you cannot get FD2Rs here.

I haven't heard if the FD1 and FD2 springs and fittings are different, but I'm guessing that they are the same, or atleast interchangeable. The spring rating may be slightly different as the K20 is heavier than the R18. Other changes are obviousely stuff like exhaust piping and seat airbags and what not.

Feel free to correct me more knowledgeable ppl, but thats what I know.

Cheers.