Yeah - recording as part of the assessment is a bit dumb, because it depends what resources are at the schools' disposal and it could put some people at a disadvantage.
Try the Con as in getting some musos? Yeah probably. For your piano/violin part you'd have no trouble finding people, I reckon, there. But this is the Con we're talking about - aiming to be professionals therefore could be available at professional prices. It'd be excellent though, especially if you can get them up to your recording studio! It seems like a lot of work for nothing though, as the recording,according to the syllabus "is not judged on its quality but rather just to display the candidate's intentions", and is not really marked, except as you say in the internal assessment.
Shoving it onto Sibelius is probably what I'd do for my fugue for the elective 2U. Doesn't really require too much effort. But for a violin and piano it'd sound absolutely shite, depending on how good your MIDI thing is. Hehe.
Anyway, good luck with your quest!