I'm coming into the discussion late, but here's my thoughts;
Mounting sucker fans usually requires tilting the radiator forward a little (lay down) are you sure that hasn't been done to your current setup? The lay down isn't typically as aggressive as 45 degrees in my experience. I used a ~2" bracket to move the upper radiator mounting forwad enough.
I believe the Hall Pheonix radiator is quite a bit thicker than a stock (or Fluidyne) radiator further restricting available room for sucker fans. In short option 2. may be the only viable one with a Hall Pheonix radiator.
In addition the recommended standoff for a flan blade is 3/4" for optimal efficiency and placing the Flex-a-lite shroud against the radiator usually results in the fan blades being too close to the radiator core. Standing off further requires even more free space to work with.
Have you considered the Fluidyne (or other e.g. Ron Davis) aluminum radiator? The newer Fuidyne is 5 core, PIM seems to have the cheapest prices at $585 and it has straight outlet/inlet tubes so you can create any standoff with a 90 degree hose. Modern M22x1.5 fittings allow for a number of modern programmable temp sensor options.
I would not recommend mounting any fan with the through core tie method that you currently have. Mirriah fans are an old school upgrade, modern curved blade fans move significantly more air then the Mirriah's will. If I was buying fans it would be modern ones, and you may already be aware the curved blade fans are pusher or sucker profile and not usually reversible like older straight profile fans. Sucker fans are more efficient than pushers.
Have you checked your under car coolant tubes for crud and sedimentation?