Any recommendations on which ones I should buy? And the pick ups need to be mounted on the hull right?

Good question.

I was going to drill and tap a fitting from the water passage on the side of the drive and then direct that water onto the side of the case since I am using an external water pickup.

I use the shimerak drive shower sorry I'm sure that's spelled wrong but i use the one that is for a alpha drive and had to rework it to fit works awesome.ill put up picks later if you like.