There are a few option in Tiki working with the recent versions from what I know.
Tiki cart (you found), the advanced shopping cart (there is a profile for this) and I recall a paypal button (I used on a Tiki19 with the plugin list to generate buy buttons from a tracker catalog).
Check those and find the one that fit your need.
I have to say that each shop usecase is different and require deeper investigation...
I’m planning soon a weekly open live session on Tiki... May be something to discuss live. ;-)