You have to have the original ones that came off the head.
If you can't find them, that head is as good as useless.
*edit*
Sounds like you only need 1.
You may be able to find one that is close, but I would advise against it. They are marked for location and directional for a reason
Each cam bore is a tiny bit different, and a tiny bit of difference makes anything but the original caps near useless.