How to start a VOIP business with low expences.. What are the best companies to contact..

I don't know which ones would be the best companies. But, how to start one as well as business plans are listed in many places on the Internet and you can see that by clicking on the following links.

Start Voip Business - Google Search

Start Voip Business Plans - Google Search

The only thing you'll get from a VoIP company is a LOW return as the market is extremely cut throat.

Telecoms, of any type, is NOT a market to get into with low investment.