Neither of those versions are available any longer. Your options are to either upgrade to the latest boxed version of Flexi, subscribe to their cloud version or shop around for a used version of 8 or 10 along with a dongle to go with it. Your existing dongle only has value if you upgrade through Flexi or one of their distributors to the latest version available.
FWIW, Flexi 8 was a problem version. Version 8.6.2 was much better.