I have a DIY project in mind. An old 90L slalom board is sitting in my garage waiting for a foil to be bolted into the fin box.

Or even bolted in to a new box slightly forward of the fin box.
So I have two burning questions...

1. Does anyone know the ideal placement of a hydrofoil.
2. Where can I get a foil fairly priced for experimenting.

I've seen the AHD videos of their board planning in about 6 knots, but I'm keen to use this in 20!

Thanks...