I've got the GT-i9300 from 2degrees firmware to whoever's interested in it.
Or if you want to do it yourself, try using Check Fus (from Play Market) on your phone and it will get you the information you need about your firmware, example here is mine:
Product Code: GT-I9300MBDNZC
and then the app will let you know if you have the latest firmware or you need to update to an official or test (if you set it up to allow test firmwares) firmware.
You can then use the Check Fus Downloader windows version or the web version to download, check and decrypt that firmware from official Samsung servers.
You can use the same method to get any firmware from Samsung servers.
It's useful in many ways I won't even mention. Some suggested that by flashing this into a parallel imported I9300 you will get the full support for Touch2Pay.
I haven't tested that theory and don't know the legal side of it, but theoretical it should work.