You can either use a stand-alone daemon, an apache install, or any other webserver -- that part's mostly just a matter of personal preference.

From the sounds of things, you already have dynamic DNS, so you don't have to worry about some complicated system where the client notifies the server when it's moved.

Anyway, the code you found should do exactly what you're looking for -- it'll bind to port 80, and listen for connections, then dispatch to the appropriate modules, based on the URI used in the SOAP connection. There's a little more info on the soaplite website, but they don't have the 'writing a server' bit done, just bits on how to modify the behavior of the responses.

The only thing I can think of is to take a look at the documentation for SOAP::Transport::HTTP, within the SOAP::Lite package. I've never used the SOAP::Transport::HTTP::Daemon, but I think I remember having seen a note about it processing requests in serial, as opposed to forking children (test it, and make sure it works for what you're trying to do)