Foods a turtle should have:
1. Reptomin. (or equivalent)
2. Red or greeen leaf lettuce. It costs about $1 at the grocery store. It's not like you have to go out of your way to get it. It lasts at least a week in the fridge, maybe longer! I throw in about half a leaf every day.
Kind of optional:
3. Cuttlebone. This one is probably the biggest pain. You find it in the bird section at petco/petsmart. You have to take the hard part off. And to answer your question, no, they don't "make" it without a backing. It is the bone from the cuttlefish, it isn't some man made contraption to annoy us and keep us away from the softer calcium inside. It's a great calcium supplement, and its pretty cheap too!

Break it up into head sized chunks for your turtle.
Things a turtle doesn't need:
1. A companion.
2. Shrimp.
3. Vitamin supplement. They get all they need from the reptomin (except vitamin D, which is made by themselves when they bask).
Good luck on your turtle adventure.

Cap-hits, not Cafits.