Am trying to catch up after returning from the MGS AGM in Menton and so have just seen this post. I'm afraid that it's rather like the old recipe for 'jugged hare' that starts by declaring 'first catch your hare'. In this instance first find your Victoria plum tree. I must admit that I have never come across one here in Cyprus. That doesn't mean that they are not out there only that I have never seen one. Then, of course, there are the factors of geography, etc, such as where in Cyprus are you gardening, at what altitude, what's your soil like, how much access do you have to water, etc, etc.
Sorry I can't be of more positive help but I'll put out feelers among my contacts regarding availability of Victoria plum trees.