[Serusers] Looking for Call termination service provider

Hi, I am looking for a VoIP wholesaler who will allow us to operate our own SIP server infrastructure while we can forward all PSTN destined calls to their gateway. I really didn't think that it would be hard to find one but I have not been successful. I have checked so far with iCallGlobe.com and Deltathree.com. Can any of you recommend us some VoIP wholesaler with quality service and competitive rate who allows this business setup? Below is logical business relation setup: Our subscriber <--->ATA setup to connect sip.ours.com<----->PSTN gateway of wholesaler.com<--->PSTN Basically we are looking for good "wholesaler.com". Any comments will be appreciated. John K.