Hi Simon,
Yes, you can. Servertastic is one of our Authorized Resellers. Any SmarterTools licenses they sell you are the same that we offer and can be supported by our team. You can see them here on our list of Resellers:
https://www.smartertools.com/company/resellers
Andrea Free
SmarterTools Inc.
877-357-6278
www.smartertools.com