There are lots of ways you could go on this. Sometimes it is a good idea to blend things together, but another approach is to make things pop out like at the produce section of an upscale grocery store. Rather than having similar things next to each other they often do "color breaks" to make the red apples jump out from next to the yellow ones. I see a lot of wall/paper sample setups and notice that most run from one basic style toward the other extreme making none really stand out. I think that if they separated red brick types with the other grays and tans each would be an individual that might add a little clarity to choice making.
A lot will depend on how much room you have to work with. If there is a lot, you may make little vignettes of masonry styles with appropriate products and landscape styles. Then you can connect them with walkways that show other products, patterns, and planting styles.
It is important for you to showcase your talents here as well. What you do to captivate people with a combination of planting style, landscape style, and product is going to impact sales for the masonry company as well as for you.
Add topography if possible. A retaining wall needs context. If you can do some more geometric grading and layout as well as some other vignettes with undulations and curvilinear layout you may inspire or captivate others who might not give the alternative a separate look.
I think the worse thing is to try to have too much variety in a small space where it is all mused together. Separation and transition are important. Again, space is going to have a lot to do with it.
