From memory (it is four years since I worked in a careers advice capacity and someone more current would need to confirm or deny this) if you want to do a 6th form scholoarship, especially with the aim of going on to do Officer training, then you need to do A levels. NVQ's, ND, etc will not be accepted, no matter what they are supposed to be equivalent to. 'Supposed' being the key word - I saw too many people who simply were not at the same level as an A level student would have been and I can't imagine the situation has improved. Sorry to be blunt, but I also came across too many people who had been given the wrong advice and had dreams/plans crushed.
If I remember correctly, the International Baccalaureate is accepted as an A level alternative.
Perhaps Disco or someone similar can give more up-to-date advice?