change IPs and have multiple IPs, need info

We are asking for information how to change IPs and have multiple IP addresses, Is there tools or services allow us to achieve this. We need to post to large site such as Craigslist, we need tools or services give us abilities to easily change to a new IP address. The more IP choices the better, preferably in the US. We are paying for the information, if you point us to tools or services that we are looking for, we will pay you. $30