I think for a proper Dual SIM phone with a better known brand will be LG KS660.

Note that it only works with 2G network

For one card two number, you can get plan from PEOPLES, which is a child company of China Mobile. http://www.hk.chinamobile.com/p_roam...o_intro_en.jsp

But, for me as an infrequent visitor to China, I bring 2 phones