Not quite sure whether you mean you want to see if your dogs will work the sheep or whether they will behave around your sheep?
If it is the first then you need to go to an experienced handler who can assess your dogs, assess you and decide if you and they can be trained. If you only have a few sheep and all you want to do is herd them in or along then a well behaved dog that can stay beside you, sit and stay will probably suffice. Equally, bucket training may well do the trick.
I bought heb wethers to train a dog and I found them fine. I know people who rave about them and people who don't. Of course, some blame the sheep, some blame the dog but they never blame themselves.
You don't say how old your dogs are or how they generally behave around livestock?