Well, I go through all the same problems when I shop around for anything new to my Amiga. Always have to tell them everything, even though they should be the expert. I often wonder if they have seen the inside of a computer themselves.
Well, SCSI is becoming outdated in the PC world, it's mostly used by servers, if they haven't made some kind of RAID setup.
I can't see why there should be so a huge difference in prices, but one reason could be that it's three different cables, for instance Centronics cable, 50 pins cable, 68 pins cable, etc.
The question of how many ports is difficult to answer. How many drives are you planning on using with the SCSI?
If one of your drives can be terminated with a jumper, you must hook this drive up as the last one on the cable, in order to get the scsi bus terminated correctly. If jumper termination isn't possible, then you also need a terminator. This way a cable with 2 connectors isn't enough. I would say go for one with 6 connectors or more.
I recommend that you bring your hdd to one of these stores, ask them to see the cable, check that it's the same one (the CyberStorm connector is 68 pins also, isn't it?) and then buy the cable if it's the right one.
If you want to use an IDE disk, you can put it on the SCSI chain and still get some of the performance of the SCSI bus, instead of the slow IDE bus. It's done through a SCSI-->IDE bridge, and I have only heard good things about it.
