If you do enough reaserch, you'll find that most US based kits are pretty crappy... the solinoids are woefull. NX is brobably the best of a bad bunch.
For a safe, efficient and reliable nitrous system- look past the 'brands'. Especially for an expensive car.
Most people would not be able to set up a dry system correctly... most will get an initial lean out.
As above... to do it properly, it's going to cost tripple your initial investment. Then once you have the whole lot up and running, you have to re-build most generic solinoids constantly to ensure eeerm 'reliability'.
PS- Dynotunenitrous.com gear is often found to be a poorer product to holley NOS.. I wouldn't use it on my scooter!
Some of the best info found about nitrous is found on:
http://www.noswizard.com/
http://forum.nitrous-advice.org/