Rather than dig down into the existing sloped soil, I was going to add dirt to build up the ground so it was more level across the front, placing the drain in as I build it up. I felt this would help prevent water flow under the house by (A) adding the drain and (B) negating much of the slope towards the house. Feel free to comment on this plan.
The question I have is not about the plan as much as it is what type of foundation/support wall to build to hold the dirt back from wanting to go under the house. Should it be a poured concrete footing type of barrier or would cemented concrete blocks work or something else all together? I would assume a moisture barrier for both would be advisable to prevent direct contact with the dirt on the concrete / blocks. I was hoping to build the wall directly under the edge of the house so I could install new skirting that would rest directly on this surface.