Re: Hello from Sydney Australia
Your options are a the disc hub method, The HD hub available locally from MBB imports and others or the SBP shifter kit.
I actually use all three and think the HD hub is the easiest solution, It also comes with a band brake. The disc hub will require an adapter between the hub and sprocket. I made mine but they are available in America from Kings. The last option is the best but most costly and labour intensive of the three options.