Hi Naveed,
In case of those Chineese SWITCHES-HUWEI & ZTE you may have to face some probs in the implementation stage.I dont know much abt ZTE & HUWEI,But I worked with another one Chineese vendor called as SHANGHAI BELL in Bangladesh.There they implemented a ALCATEL-S12 Kind of Switch for which they did lot of alterations in the core software as per requirements.
Rgds
Sunil