To answer my own question:
I only had a long cage mech, so stuck with that, just shortened the chain a bit.
Up front I went with a Hope bash and an inner bash from these guys:
http://www.bbgbashguard.com/Mountainbike.html
it comes from the USA, came in 3 days, marked as ‘gift’ so no tax to pay.
I also went with an on-one deep drop chainring.
Next time, I’ll stick with a standard unramped chainring to save an ounce and a couple of quid. I would get the same inner and would probably buy an outer bash from bbg too.