Delica Canada | Mitsubishi Van Club

I've been looking at roof racks and it seems that a lot of people use three racks. The Rhino rack people even make a package of three racks for the Delica. Is this more for looks rather than a structural thing. I have two racks on my big Chevi van and they will hold a lot of material. Also wondering if anyone out there has put on a side ladder and what type of fastening system they used especially for the bottom of the ladder. Seems to be rather busy under the body on the side of the van for fastening purposes.
I've searched the various forums but not much specific information. Thanks.