Woz/Steve - thank you.
Yes, I'm diving in a 5mm wetsuit and I don't think I need a STA as both cambands pass all the way through both the backplate and the wing and the wing itself has a pair of the little stabiliser rubbers for a single tank too.
OK - I think I have a sensible solution here if anyone would care to comment:
Based on the assumption that my BP&W setup with aluminium plate would require the same or less weight than my past Aqualung Zuma BCD (that was 7-8kg but likely was overweighted. Bear in mind I only do single tank diving in Mediterranean or warmer water in a 5mm wetsuit) - then having the same 8kg capcity on the new setup should be plenty.
I want to have as little 'bulk' on the rig as possible.
So, here goes:
-my two Mares trim pockets go on the upper tank band
-I buy a pair of the small XDeep weight pockets. These hold a maximum of 2kg each (so are really compact, I think the photo actually shows the medium) and are quick release - but held by a good quality pinch clip. So to all intents and purposes they are just the same as a pair of trim pockets, just adding that little bit of a 'ditchable' factor. They are also one of the few pockets that physically bolt onto the backplate so are sure not to slide around.
That lot gives me a maximum weight capacity of 8kg and lets me distribute it around without having any oversized pockets with weight flopping around inside them.
If in the future I want to move the weight out of the XDeep pockets and onto the camband I can just pick up another cheap pair of mares pockets.
Sound sensible?
I could go for the medium pocket (which is still quite compact) but that would give me a max weight capacity of 10kg (2x2kg camband trim pockets and 2x3kg in the medium pockets) which seems excessive.