I would avoid specially selected bits of work, as they beg the question "How much help was given? What's his/her work usually like?"
As in The Y5 or Y6 project... I know that some children do all the work & research themselves. I also know that some have a lot of help from parents - some are even almost entirely completed at home by 'helpful' parents. So some panels may take all projects with a pinch of salt (especially if the teacher has written "please pass my congratulations onto your parents" on it