Definitely shoot 60i versus 30p. It is easier for a good de-interlacer to reconstruct spacial detail, than for a re-timer to reconstruct temporal detail.
Definitely get your shutter speed at 120 (or more if you can.) Motion blur that wouldn’t be there if you actually recorded at that speed will destroy the illusion.
Regardless, after you’ve conformed the new progressive frames to 24p, you can then use optical flow in Motion 3 to take it down even further. Optical Flow works best on progressive material, and the results can be amazing. It will take forever to analyze, but after that you can play with the timing as fast as your system allows.