not sure if this would be appropriate, however I am a long term user of livedrive.com/?tid=PC8KVD3P
It is an unlimited backup solution that would give you all the features that you are after for about £5 per month.
it works by installing their software package on your pc, you can then select the folder/folders that you wish to monitor, and it will in the background back up all the files onto their servers, there is no interaction required by yourself.
you can then give your dad the email address and password to the account and anything that is stored in the folder that you have marked is backed up safely to the web portal for him to view and download as he wishes.
Sorry if this is not what you want but I have been very pleased with it myself and it is also a lot more secure than opening up ports to your computer.
it also backs up all your files securely without you having to worry if the hard drive on your computer dies.
Thanks
Philip