dynamic ip addresses and wordpress.

Hi,

when using cloud servers with AWS or RackSpace, can changes with ip addresses affect WordPress or plugins in any way ?

I am currently trying out AWS's free tier as well as RackSpace and I understand that if any virtual private server is rebuilt the ip changes unless you pay extra for a dedicated ip.
I guess if one is using ProSites or has any any e commerce involved then an SSL and dedicated ip would be needed, so would such a scenario solve this problem ? This is using the assumption that various ip address will affect WordPress.

I am also considering WHMCS Provisioning plugin, would WHMCS, WordPress and WP plugins be affected in any way on servers when having ip addresses that change ? And if so what would be the effects and how can this be solved ?

Any kind assistance in this would be greatly appreciated.

Kind regards,

RC.