Best source for buying seller leads

[Michael Clay]

I'm looking for a good lead source for potential sellers that has the phone #s included with the addresses.  I'm currently using prospectnow and the strong-majority of their leads are bad numbers. I understand that there will always be a good amount of bad #s but with prospectnow around 80%+ (my personal experience) are bad #s. The goal is to call on the leads to buy as investment properties. Any help would be greatly appreciated!