Yes, you can edit the job and select the new service, which would then automatically modify the price. But you might want to consider creating a matrix. This allows you to easily choose which specific snow service was performed.
You can print a matrix but you cannot schedule it. Another option is to quickly create a new Job Cluster (Schedule | Job Cluster) and add a lot of customers, or edit an existing Job Cluster. But there's no way to tag customers like you mentioned.