As Zoran said HyDrive OBKI1 is made in South Australia and in my opinion superior to Sea Star. The cylinder in the old units was made from brass unlike the ally in the Sea Star. Depending on the outboard you have you mat need a different model. The above model is suitable for Mercs.
I have Sea Star in my boat because she was fitted with it new, almost 10 years old without any problems and I have auto pilot too.
About 20 years ago I replaced a cable steering and I used the Hy Drive just because it was Aus made, no issues in the 10 years I owned the boat .