This summer I want to do a "bait and switch" type of fishing with
Shark in mind.

Has anyone ever done this before? I am a bit at a loss of what to use
for leader and fly when it comes to shark.

Here in Maine the species that may show up to chum are , Blue,
Thresher, Porbeagle, Mako, and general dogfish. I guess Whites CAN
come in, but they are protected.

When fishing with regular boat rods, I have become relatively
comfortable fishing for these guys, but have never put a fly out to
one.