Do they make twin (2CKT) for the bolt-in type breakers?

Yep 2-pole and 3-pole, even 4 and 6 pole. But if you mean skinnies, nope! Never seen one.

Yes, I meant the thin ones. the same size as one thick.

This is one of the big differences between "panelboards" and "loadcenters". The obsolete Bulldog/ITE/Seimens Pushmatic product line had bolt-in twin breakers, but it was marketed as a loadcenter.