Yes 3 sim cards and it's better if they are not from the same provider.
However you should learn more about how to do new accounts by reading the forum and/or buying the book they are selling here because Amazon is great at detecting stealth accounts.
The bottom line is....You need to have separate IP's for each Account. You can use any of the following:
1. VPN
2. Sim Data
3. Mifi/Dongle
4. Phone Tethering