Good luck and maybe post-Christmas sales will give you an opportunity to get the Aulos. If it does, please post your thoughts on the sound, I would still like to know!
Incidentally, an advantage of the keyed models tends to be that you can play high C# without having to use your knee to block the end, which is probably more useful than being able to get low C#. The more-or-less regular Ø1-345-7 apparently works on the Symphony.