Network Attached Storage over Internet
If you cannot register for DynDNS for dynamic DNS, register at no-ip.org and install their updater on your Windows machine. Lots of people want to buy a NAS these days. I own a QNAP just for the hell of it, but a regular windows PC is fine with FTP. Install a battery backup unit for it, your internet connection and setup a remote administration tool like LogMeIn. This way you can easily get to your computer to repair any FTP issues you have.