My question is if I set up VPN at home will there be an issue with my external IP adress changeing. I know that service providers will periodicly change your IP address. Is there a way around this?
It depends a lot on your ISP and how they manage their customer connections.
For example, For their residential customers, Century Link uses a rotating pool of IP's for a specific group of customers. It causes your IP to change multiple times per day. They claim it is for customer security but rotating IP's does NOT improve security on the Internet. What it does do is prevent their customers from hosting webservers and game servers. In many cases, if you call them, you can get what is called a "sticky IP" which is based on the MAC address of the WAN port on the Modem. You just need to tell them you are using cameras that you want to be able to view from the Internet and they will usually give you a sticky IP. They do charge for the service though.
With most of the Cable companies, your IP will remain the same unless you change the first device connected to the Internet Ethernet port on the Modem or if you clone a new MAC address in the Router.