I believe they all need to have 2 mics, not sure about a grand but I once miced an upright with one at the top with the lid open and one at the bottom with the front panel taken off. I used to own a Leslie and the same applies here one for the horn and one for the bottom rotory speaker. I'm sure there may be some other ways, but that's how I did them and I used SM 57 for them.
I would play around with different things. Though I would mic it differently. I like a stereo effect in my leslie sound, so I might use 2 mics on the top and 2 on the bottom.
Stick with the dynamics for now. (57s should be fine for this)
If they don't work, try the 990s, but don't put them too close to the Leslie.