I have an ECO from a few years ago but I'm not sure if you can still get them.
I have a suggestion. Make sure you get one that allows you to open the front window allowing the airconditioning to reach your pup. You also need to seal between that canopy and the ute rear window. I did this by...
An old thread and OP has probably worked something out but here is my 2c for anyone else looking for a solution.
What I did for my dog was to place a small motorbike tube between the canopy front window and the rear sliding window of the ute cabin.
I then inflated the tube to create a seal...
I just replaced mine today. I didn't have to remove the alternator to do it. I sourced the replacement from Bursons for $91 and they had it in stock.
So from having the horrible noise to looking at this thread to having the problem fixed all in about 4 hours.
