Right I just took a peek at that WiKi and saw
Western Digital "MyBook Essential Edition", (model-WD5000C032) looks like it will work. I have that drive attached to my 2003 Server so I'm going to copy the info off that to my 1TB Mybook , then with WBFS Manager copy the contents of the Maxtor over to the 500GB MyBook and try that onn my Wii.
I looked back on that Wiki and it shows my Maxtor as being compatiable. I put uloader on the SD card and also the IOS it reccomends. Installed both an Uloader saw the drive. Exited out tried USB-Loader GX again and it works.
Now I can move my game disks to the drive. I alreay lost one disk so I have to look for a replacement.