The right current Avantalk dongle for hearing aids is the C82 LE Audio, which uses the new Bluetooth low energy audio protocol.
I am using one of these to stream high quality music from my iPad to my Resound Vivias, which are also known as Costco Jabra EP 30. The sound quality is really excellent and Avantalk are currently working on the firmware to make handling improvements. You can buy the C82 LEA on Amazon for little money.
I’m not sure that the C82 HA actually exists as a current model now? @PhoebeY