Looks like a lot of trouble shooting has occurred already, but I can confirm that a 2 GB SanDisk Ultra (SDCFG-002G-A110 works on an Amiga 3000 with a SCSI-IDE convertor.
The SCSI IDE convertor was just a generic bought off of ebay, and the IDE CF bracket was likewise. On the model's I have, the IDE CF bracket has a floppy power connector and the SCSI-IDE adapter has a standard Molex on it. Both have to be plugged in for it to work.
The standard scsi.device has no problems seeing it, or detecting the correct settings for the CF card.
I just got workbench installed on it last night. It's not instant on, but it's a lot faster than my A2000 booting off of a real 2 GB SCSI hard drive.
(I'd say it's about a 3 second boot...)
I can try to find out the model numbers on the CF reader and the SCSI convertor, if you need them.
