In Irish climate I really doubt if you need 10w60 or even 15w50 - unless you race or rally really hard (but then you would probably already have your own reliable supplier )
Go for Millers CFS 10w40 - should be easy enough to get. Or if you can get it - Motul X-cess should be also fine.
Motul 300V is also very good choice, but you need to remember about changing it quite often (like every 7000km the best)
Personally I would avoid Castrol oils after I've seen what dirt it leaves in cylinders - but it's the case of personal choice after all either...