All the parts should be available from Opie Oils. Their filters are mahle or Knecht, and oil, take your pick. Orders over 60 quid are post free. They nearly always have some sort of discount going on so price it all up, factor in your discount and see how it compares.
Also now if you order oil and filter they will send you a collapsible disposable funnel and a little bag for all the rubbish which is a nice touch. Good folks, I use them a lot.
I’m a fan of Motorworks. They are very good over the phone for help and advice. I haven’t had a bmw for about 2 years now but when I had one that was my go to. Of course Brexit doesn’t help. JJH