What screw/fitting to use on this wall?
Shelves like the one described can carry a significant load and things are regularly being put on and off, increasing the dynamic load. Unfortunately, from the illustration (and the appearance of the listed item on the sellers website), there are only two screw holes at each end. This puts a serious load on each attachment point.

Plasterboard or even plaster by itself is not a very good support for shelving screws unless there are many attachment points.  I would try to find framing members, usually vertical studs, and align the screws on at least one end with them. You can use a stud finder to locate the stud.



If you cannot align all the screws with studs, on either or both ends, or if the wall is made of plaster over hollow blocks, I would use toggle type anchors instead of the screw in anchors you listed.



These spread the load over  larger area of the plasterboard than screw in anchors, reducing the risk of pullout.

If you cannot align the screws with framing members, a stronger solution would be to mount a board on the wall first, screwing the board to multiple studs, then mounting the shelf to the board with wood screws.

 Images and links are illustrative only, not an endorsement of goods or sources