Wayne,
5w-40 synthetic for the engine, have a look at something like the Motul 8100 Xcess 5w-40, Fuchs Titan Supersyn 5w-40 here
http://www.opieoils.co.uk/c-656-5w-40.aspx If you want to go all out the ester based Silkolene Pro S 5w-40.
For the filter, have a look at some filter foam oil
http://www.opieoils.co.uk/c-639-clea...additives.aspx
Cheers
Guy