I have used similar Seahorse cases on the standard Givi rack on my 06. Happy Trail sells a set of mounting pucks that adapt any flat sided case to tubular racks like the Givi. Seahorse sells locking cases for a LOT less than Pelicans.
On my 13 Glee, I am going with the Givi PL 3101 rack ($180), Seahorse 720 (left) / 710 (right) cases ($130), and the HT Pucks ($80) for a total of just under $400 for the entire system. I use reusable grocery bags for case liners. Mostly, I am just throwing gloves, water bottles, and jacket liners in, so I have no issue with side loader cases.
2017 Honda Africa Twin DCT
2013 Honda CB1100
2015 Honda Grom