Congrats on the new presses.
I would recommend that you mount the LnL AP so that you ensure the table does not move when you pull down hard on the press. Nothing is worse than a wobbly press. My bench is against a wall in my garage. I mounted the LnL AP on a 2"x6" with countersunk holes on the bottom to allow carriage bolts and fender washers to be flush mounted on the bottom of the wood. The plank is long enough to allow the press to hang over the end of the table to allow access to everything under it including the primer drop chute. The other end of the wood is flush against the wall and anchored to the wall stud with an inverted bookshelf bracket. This offsets the tilting motion of the press hanging over the edge of the table.

The height of the press and handle make a big difference when loading big batches. You want a comfortable and natural height when performing hundreds of handle pulls and pushes (primer seating). The height of the press is perfect for loading while either standing or sitting.

I did the same with my single stage press which is a Lee Breechlock Challenger where I have to crank down when sizing .308 and .223 brass. For that press, a 2x4 is sufficient.