What do I need to get or do to get Speed Daddy GP headers to work on my Bonne?

Besides a GP trans dipstick tube

You may have to modify the front left trans mount, it'* no big deal. Not sure but I think you will also need to change the down pipe.

Do you mean just notch the trans mount?

Yep, I just ground off the top a bit.

you might need to move the fans and shroud back a bit, i had to on my 95, i had to cut into the radiator cover

You should be all set. No mount sticking up to mod, no worries of fans, no issues beyond swapping the dipstick tube.

One bit of advice is to take a close look at where they put the O2 bung. I have seen some that hit the body of the W-body cars and would do the same here. However a buddy that bought and installed them last week mentioned the bung was in a different location.

Buy Torca clamps for the front to crossover and crossover to rear, and it would be nice to have a couple underneath as well, but that depends on how you decide to connect.