Where to start
Please see 2 links below (before I forget them again)
These fellas below do an IMP KIT, engine, throttle bodies and all you will need for your imp conversion engine wise
https://www.motorworks.co.uk/vlive/Home/index.php
And of course these fellas as a source for BMW motorcyle parts (BMW motorcycle breakers)
https://james-sherlock.co.uk/
Please see 2 links below (before I forget them again)
These fellas below do an IMP KIT, engine, throttle bodies and all you will need for your imp conversion engine wise
https://www.motorworks.co.uk/vlive/Home/index.php
And of course these fellas as a source for BMW motorcyle parts (BMW motorcycle breakers)
https://james-sherlock.co.uk/