many blogs on subdomains with a drop down picking one

Does anyone know if there is a plugin that will do this:

I am in the process of creating a blog that has the potential to be replicated in other areas. Each time the blog concept is replicated it will be on a subdomain of the main domain, for example main domain is mydomain.com replicated blogs are by various towns, mytown1.mydomain.com mytown2.mydomain.com. Those towns can be in other states. What I want is a drop down that would first have the state then once a state is chosen it would show the towns that have this blog. Once someone picked their town, it would redirect them to the proper sub domain. I would also like to see a breadcrumb nav that takes into account the sub domain.

Does anyone know of a plugin that will do this?

Thanks!