Hey,
what are you currently using? Do you get dynamic IP Addresses from your ISP (Internet Service Provider)? If yes, alls ISP normally offers that you can switch from a dynamic public ip to a static one and maybe get 3-4 Adresses to use for your business. It´s normaly for a small amount of charge and they change that.
I would also suggest you speak with your ISP about the topic but it shouldnt be a big deal!
Regards