1. The Blizzard SCSI-Kit IV is only SCSI-II,SCSI-I Drives will work, too.
A few Examples of compatible Drives are
here.The '18Gb IBM Ultra3 U160 SCSI Hard Drive 10000 RPM SCA' is a bit too modern, it will not fit.
There is possibly a Interface available to connect it to SCSI-II - but these things are always a bit expensive
and you will never be able to get the full speed of the Drive
(a 10,000 rpm drive is of course very fast, may be loud and will need good cooling)
2. If you use only internal Drives, the built-in Terminator
will be used.
3. It depends on the Drive at the End of the Chain, many SCSI Devices have a bulit-in Terminator, sometimes even active, which can be enabled by a Jumper.
Otherwise, a 50-pin active Terminator would be the best solution.
I found the Manual
here.