Dear Charl
Have a look at my reply under the AS Music topic - student forum. It's a good idea to choose longer pieces, as they usually contain a certain amount of repeated material, and therefore there is less to learn to make up a suitable length programme.
I can advise you on flute pieces, as I teach flute to A level music students. The Faure Sicilienne is a good choice, very popular for AS performances, and the right length and level. Another good choice is the Mozart Dove Sono, which includes a slow and a faster section, is not too demanding note-wise, and takes around 4 minutes. Other popular, but shorter choices are Anitra's Dance and Tico Tico. You should aim for Grade 5 level pieces, as Grade 4 pieces will reduce your mark.
It's probably even more important to check the length of piano pieces, as some of the ones set for exams are very short. Generally, slower pieces take longer than faster ones (which seems obvious, but it's worth stating
). You can combine a longer, slower piece with a shorter, faster one for contrast.
You can probably use both instruments for the performance elements of the course; the exact requirements vary from board to board, but if you will be doing Edexcel you can use one instrument for the 'Performing during the course' element, and the other for the final performance.
Hope this helps
