If your local stores don't have them, you can find online sources. Get a look at the photos online--sometimes stores don't know they have Sansevieria because the scientific name is rarely used. The name the stores use can depend upon the varietal; mother-in-law's tongue and snake plant are only two of _many_ names for this genus, of which there are possibly several dozen species! One source says there are around 60 of them:
Water When Dry: Sansevieria trifasciata 'Moonshine'
A great set of photos are here:
SANSEVIERIA species and cultivars
However, the photographer gives only scientific names at that site.
Even if you can't find Sansevieria specifically, take a look at the store plants. Reject spiny cacti and ferns (too fragile) and other plants that you can easily push down with your hand, and reject anything that's too big. What's left? Is there anything you might want to try? Don't spend a lot, because whatever you _think_ is going to work may not.
Here's what I've had the best luck with so far: Pothos (doesn't seem to be a problem when the snake crawls over it so far), Sansevieria sp., and ZZ plant (Zamioculcas Zamiifolia ). You can see info about ZZ here:
ZZ plant - Zamioculcas Zamiifolia
ZZ will eventually be a problem unless you have a tall vivarium--it gets 2-3 feet tall or more. However, I'm using some small shoots to begin with. It has bulblets underground & is easy to divide, so I just cut some young, small shoots off a potted plant & stuck them in the vivarium; so far, it's ok, but it will outgrow my BPs vivarium.
Oh, I also have hen & chicks (Sempervivum tectorum). Info here:
Hen and chicks - Wikipedia, the free encyclopedia
That's only been in for a couple months & is hanging in there. Another tough plant with no spines.
Good luck!