I used these when we had a store
Car & Truck Custom Seat Covers - Automotive Seat Cover Manufacturer - Seat Savers Plus
I have a set on my personal vehicle and love them still. They run about $100-120 per row, meaning if you have just the front and rear seats, you will spend about $250. They are cotton canvas, pretty easy to remove and put through the washer and dryer. They are custom fitted and if you need help figuring out what seats you have, post pictures here. I only missed on set and that was the customer trying to order them with having the truck for me to see.