On Galicia Negra:
Some people have had serious issues getting these to both root and grow. My GN's lineage of ownership is plant-creator/Hooray>Kriya>Bass and for me, it's one of my most productive varieties in terms of just overall growth. The roots are fat, the tree is tall, the trunk is widening all the time, and the leaves are strong and resistant to rust. I guess this post might serve more as a sourcing recommendation rather than an outright endorsement of the varietal itself; I mean, the fruit I've had is just fine but 2017 will be its second year so let's see how it improves. If nothing else, it'll make for great rootstock.
On O'Rourke:
Man, I killed more of these in transplanting than I have with any single other varietal. It has been so hard for me to get this going. I finally have one plant and I started out with something like seven or eight. Maybe it's just me, maybe not. I guess if you decide on O'Rourke, and if my experience is anything to go by, be patient during the rooting phase.
Calvert:
If you can find one without debilitating FMV, let me know. The one I had was already rooted but died within a few weeks. It was about the size of a thumb and wasn't moving at all. Then one day, it just croaked. I hear it's great, though.