Or the other option is to speak to your neighbours and see who they use. Our scanner would be reluctant to make a trip just for us, but is happy to call in on us on the way back from another local job.
BTW, when we have ours scanned, the scanner can't be bothered setting up the scanning crate just for our wee flock, so instead uses a backpack type scanner usually used for cattle. This means that you may not need a sheep scanner as such, but actually a call in on the way back from seeing some local cows may work too?