[asterisk-biz] PSTN termination provider

Hi,
I am looking for a PSTN termination provider that can cover Asia including Singapore, HK, and major cities of China.    Preferably, we like to also buy a few DIDs from  a number of Asia cities as well so a provider that can support PSTN orgination is a plus. 
Can anyone give some suggestions on which one to use?

Thanks,
Mark