Yes, thats certainly possible.
If your files stay on your computer at home, you need to configure a webserver to be accesible from the internet, and host for instance FirePlay there.
If you copy your files to your 25G web-hoster then you could install firefly on there, (only possible if you got a rootshell, or something similiar, plain http/ftp won’t do) then you could do the same.
Or, you could just use bonjour-proxy to forward your firefly server from home to anyone else, depending on how open (or closed) your home network is to the internet.