| Answer for Electric sheep,
Ithe leo vinci is a full system and does require a powercommander to be fitted(so long as you have the latest ECU fitted).
Cost is £1600 +vat for the 54mm and £1800 +vat for the 57mm.
You will also have to add the cost of altering the pipes to clear the swingarm and to have the PC111 fitted and set up(about £5-600).
The 54mm is quite ok if you are not going any further in the future but well worth spending the extra £200 if you want to go the cam and head route later on (as i do).
hope this helps
Butch | 
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