Thanks Bernie, I had thought of BACKPACKERS, but as that isn't exactly clothing, I wasn't sure. Thanks for BAT RUNS, but that throws out the word VIPER I had for 18A with VIP for 6p and ER for I think. Hope you've got that, but thanks anyway.
Bernie said Rat Runs.
re the other clue, the definition is trekkers.
the word 'clothing' is there to show that the word 'Backs' (supports) is worn by the word 'Packer' (Kerry Packer). ie packer inside backs=backpackers.