seat covers - how to choose, re: air bags

i found some towel- like seat covers on CARid.com that have the name TOYOTA on them - they are tan and match the cloth interior of my '13 Prius. they fit loosely over the seat and look pretty good. they do not make covers for the back i don't think.. they might be OK. i can't figure out what kind of seats are in my car (they have photos online you are supposed to select) I've read complaints about online seat covers, i.e. ease of installation, and blocking the airbags. I don't want to spend too much.
Why doesn't Toyota make special seat covers for their cars ?? they would make a FORTUNE.