Not quite Home Workshop but I couldn't find a better place to put this.

I want to plant an Omega (aka George Wilson) plum tree. They are partially self fertile but to get the best crop from them they need another species of plum tree as a pollinator. There are a few varieties that are suitable but I want one if possible that is most like the Omega in flavour and firmness.

I'm hoping there is someone on here who knows the Omega plum and can advise on a good choice of pollinator based on my requirement of taste and firmness.

Pollinators that I have identified so far are, Billington, Elephant Heart, Burbank, there may be others. However I am unsure about their respective taste and firmness qualities. Hence this post. 

Thanks.