Hi Fiona,
my favourite bike shop here in Germany is Radsport Rose (check ou www. roseversand.de) . They have a huge store (4 floors with a few thousand square meters) and give best advice. They have any kind of bicycles and bike- components in stock and you can adjust any part you like to your requirements. Since they build up every bike according to the customers needs, it may take a few days before you receive the bike. But, as far as I know, they can also ship it.
The disadvantage of Rose (for you) is, that it is not in the direct vicinity of Frankfurt. (At least not in Germans consideration, as I know that distances in Australia are differrent) It is approx. 250 km north west of Frankfurt in Bocholt, near the dutch border.
If you need any further help, do not hesitate to contact me.
So long
Christof