Sorry everybody - got tied up (not literally) earlier so unable to post result yet. Will do it by tomorrow morning at the latest when I've had the chance to go through all the entries and give them due consideration.
Thanks for your patience folks and apologies for what seems to have been a tricky solution to clue. I've plumped for Chris's effort at #2 after much deliberation this morning.
Preparation for combat op? (4,4)
Your prize is two video clips, as I may have offered my first choice as a prize before: