There are two completely different types of "reverse mount adapters" for close-up/macro use:
1: The classic "lens reversing ring": These rings have a male filter thread on one end and a lens flange on the other. This is the type Derrel referred to. Nikon's BR-2 ring is this type of reversing ring. It allows you to mount any lens with a 52mm filter thread directly onto a camera body, or onto tubes or bellows, with the lens reversed (front element facing sensor). All functions, including iris stop down, are completely manual and there is no focusing adjustment, per se. When using zooms, there is some magnification adjustment available when you zoom, but the focusing ring does almost nothing. The 50mm f/1.8 works extremely well this way and many mid-range zooms (modest wide to modest tele) also deliver good results as some zoom settings.
2: The rings most often termed "macro coupler". Theses rings have male filter threads on both ends. With this type of coupler, one lens is mounted normally on the body and the second lens is reversed and mounted onto the front of the first. This second reversed lens functions as a well correct and very strong closeup lens. All automation available in the lens that is mounted normally is retained and a modest amount of focusing is possible. Zooming will also produce a reasonable change in magnification. The reversed second lens should generally be a very fast lens; your 50mm f/1.8 will work well in this position. For the lenses you list, you would use one with 52mm male threads on both sides.
