i think its these terminators.

they mount directly in front of the drive in a pass-through configuration inside a g5 - if you are using internal drives.

ultra 320:
http://www.tmcscsi.com/cgi-local/Sof...e81+1116763979

ultra160:
http://www.tmcscsi.com/cgi-local/Sof...e81+1116657592