thats the kit i've used. it comes as a kit though so you need to know how to solder and put together a circuit board.

has been working perfectly in mine for over 2 years now although i also run an aftermarket ecu. i do believe that with the factory ecu the shift points for the gearbox will be affected and often the fitment of a secondary correction device is required. one to change the signal to the cluster and then another to change the signal back from the cluster to the ecu to keep the gearbox functioning as it should.

you don't need to change speedo gears in the gearbox to get it closer first.