I've got to go through the Sydney 147's AC as a priority, need to stock up on the double o-rings beforehand.
Which (sort-of) local FCA or indie supplier is best at present for these?
You's be better off looking at A/C specialists to source them from.
I'd done my homework in advance. ;)
Highgate - nope.
Ashdown - nope.
Würth - nope.
Who have I missed?
Buy a bulk kit of A/C specific O rings from eBay?
Yes, I found the Romanian bloke in France selling sets of one each size (three rings), not ideal as the size mix ratio is off.
I can make up twenty-five "kits" of three small, two medium, two large OEM seals ex-Poland for $230-odd including courier, so about $9/car on my doormat. It's tempting.
Just which O rings are you after ?
I've got to replace the hardlines from the firewall, splice in a new flex portion where the radiator shroud has chafed it, replace towbar-damaged condenser, fit a new drier and finally, renew the displacement modulation valve in the compressor. So, pretty much all the double O-rings from the windscreen forward plus the compressor pad seals - not a fan of re-using when they've got a few years and heat cycles through them.