Hi Matt,
Is the S14 Standard? If its standard than I would use a 5w-40 synthetic and you will find those through the link below.
http://www.opieoils.co.uk/c-656-5w-40.aspx
Out of those, the best ones are the Fuchs/Silkolene Pro S, Millers CFS/CFS NT+, Motul Sport/300V, Red Line and Gulf Competition. The Motul 8100 X-Cess, Millers XF Longlife, Castrol Edge/Magnatec, Fuchs GT1 XTL/Supersyn, Shell Helix and Mobil Super 3000 are good, cheaper alternatives
If its modified heavily for example running 350Bhp+ than a good 10w50 would be the more suitable choice.
As for the filter, ive added it below.
https://www.opieoils.co.uk/p-74028-g...il-filter.aspx
If you use the code SXOC, you qualify for 10% off at the checkout.
Regards
Jack