Legitimate caller id spoofing, how to do?

[tntpower]

I am in the feasibility research process to build a website that takes advantages of VoIP and legitimate caller id spoofing to serve a niche market.

Legitimate caller id spoofing is very important in this business. Basically, my prospective clients register their phone numbers, and I use VoIP to call their customers on behalf of them. Caller ID display on their customers' phone will be my client phone number.

I am brand new to this type of business. Any suggestion is highly appreciated.

Thank you,

T.