Silk Road Boots
I am planning on doing a very similar trip next year - basically UK to Hong Kong, via Russia, Mongolia and then China.
I have read a lot of posts regarding boots and what to wear and what not to wear, and the advice I can give you from personal experience is dont scrimp on safety. Get the best support for your ankles and shins you can, while still being able to walk in the boot and not look like Robocop! One good off and the trip of a lifetime turns into a trip from hell!
I would recommend the following boots, based on thier design intent:
> Gaerne Balance Oil boot
> Alpine Stars Scout WP
> Oxtar/TCX infinity Touring boot
> Sidi Adventure rain boot
> Sidi Discovery rain boot
Of these I have the Sidi Discovery boots and they are, IMHO, the dukz gutz. They are a 3/4 style MX boot - nearly all the protection of a full-on MX boot but with the added ability to be able to walk in them for hours - they really are that comfortable.
I hope this helps,