Ah - OK.... didn't catch that in your first post
You 'could' do this internally ran up/down setup, it would just be custom... we don't have a 'kit' version of the parts - you can buy the individual pieces easily though, they are all available separately from your Hobie supplier (I notice you're in Australia - so you'd have all the same parts that we do here in the USA as well)
You'll need some turning blocks for the strings to run around - screws and nuts to mount the blocks, and of course the handles and lines.
All the parts can be seen and part numbers found on pages 36 & 37 of our accessory catalog. If you don't have a printed copy - its also a free download here:
http://www.hobiecat.com/support/catalog-request/