Rather than using a WA lens which can lead to distortion, why not take numerous images with a zoom lens then photo-merge them together.
You will end up with a rather large image but, downsizing an overly large image will lead to a superior image, IQ wise.
It sounds very easy ON PAPER. In reality it is not an easy task. In the overlapping area of the two images, everything must be identical, otherwise you will have "ghost image" on the element that are not identical. In landscape shooting, if there are any movement of the grasses, leaves, branches due to wind. you will not have identical image in the overlapping area. You will end up with ghost, especially in pixel level. If the picture has a stream, then all bets are off. the flowing water will become the "ghost" in the overlapping area.
You can spend hours to make it almost perfect. Is it worthy of your time?? I only do photo stitching if I do not have any other option, or do it just for the fun of it. Using an UWA ( with tilting) is still the best option.