Well, it's kinda messy with early scsi, Apple, zip-drives and some others actually used DB25 (same as the parallell port) as scsi connector, and there were other more or less obvious connectors aswell.
For me, however, the centronics 50 pin connector is SCSI-1, even though it was also commonly used with scsi-2 units aswell.
The falcon connector is what I consider SCSI-2, it's called MD50, the scsi-2 wide version is called MD68.
Wikipedia has a decent article about SCSI connectors and it has this to say:
With the arrival of SCSI-2, the situation was a bit less chaotic. For narrow SCSI, most manufacturers used the MD50, also sometimes referred to as a Micro DB50, High Density or HD50, Half-Pitch or HP50, or MiniHonda
In all honesty, if you go with an IDC50 to MD50 connector or a centronics 50pin doesn't matter, as long as you find the correct cable between that and the falcon. Both work just as good with SCSI-2.
Btw, justto be clear, you will need 2 cables
to hook up the CosmosEx to falcon. I am pretty sure you will not find a male
MD50 to IDC cable to be able to hook it up with just 1 cable.