Originally Posted by mev

One additional suggestion. Post a question in Lonely Planet Thorn Tree forums for particular countries of the following format:

(Uzbekistan): Where can I find outdoor stores in Tashkent to buy winter clothes, sleeping bag, ...

While I haven't been there, I've traveled enough to expect Tashkent, Dushanbe, Astana, Kashgar and similar large cities to have certain amounts of camping stores with basics like a warm sleeping bag. Particularly those areas closer to the Himalaya and places tourists might come. This doesn't work if you aren't normal sizes and likely might not be the newest/lightest stuff, but my travels in similar areas suggests it can be found. The trick is how to find this in advance.

Hence, posting to a travel-related forum like Lonely Planet will likely dig up more specific knowledge.

I share djb's concern about using postal services unless you actually have familiarity (or local contact who can navigate the system).