Thanks for the suggestions for cuts - I'll give it a try (so far I've been too nervous about the poor plants to take the knife to them).
As for transport, for the first two years of doing loads of cuttings/seed-raised plants in the UK, we were fortunate that our co-owners drove out to Greece at more or less the right time in late autumn with their car loaded with plants (still in their pots) double-banked in cardboard boxes. We followed a week or so later and the plants had survived both the journey and the short period before we arrived reasonably well. In 2010, we took them by plane. We first replaced their pots with small plastic bags and then laid them head to toe in layers in double-walled cardboard boxes packing them with paper where they seemed to be at risk of moving around too much. We took arouond 100 plants in three boxes (and no other hold luggage) and didn't have any trouble with the airline. By and large, the plants were OK, though ironically it was the ones that were a bit pot-bound that came out looking freshest. Cistuses looked the sickest which is not surprising as they hate root disturbance. We have yet to see how well they'll survive this summer.