Xiaomi mi3 buying guide

Hello ppl, I will be in Beijing for a few days and I was planning to buy a xiaomi mi3 ,here are my few queries, I live in India and the operating 3G frequency here is UMTS 2100, so my doubt is if I buy a tegra 4 version mi3 ,will it work in India ,I only need 2g and 3G facilities(4g not yet operational in India),so will tegra 4 work or do I need to buy the snapdragon 800 version.My second doubt ,is the build quality decent...?(couldn't come to a conclusion by looking at the review videos). And since I'm new to the Beijing ,I don't know where to buy it here,so if anyone could provide me the details ,it would be of great help(is it better to order online on xiaomi website online or buy in a store)