Connecting External CD-Recorder

I'm going to connect an external Plextor 8/2/20 to a powertower pro 225 which has a 3940uw inside. I am using the internal fastbus for the boot drive and an individual port off the 3940uw to each of my (2) 9.1gig drives for audio, which I currently have mounted internally. The question is which is the best port to use to connect this etternal cd-burner? I have considered using one of the external connectors on the 3940uw but fear it might compromise the performance of the fast hard drives, since it is a 50 pin. Connection-wise it appears the SCSI connector on the back of the machine would be the easiest, but that goes to the computers internal slow bus I believe. Any help would be appreciated.
Thank You.

[ppine]

Connect it to the external SCSI of the PTP. I have one of my 8x plextors on it, and have had no throughput issues at all...

burn, baby burn...

[Jonny Atack]

I have a Plextor 822 on SCSI bus 1 on my Mac 9600. Never a throughput problem. Not even one bad burn. Bus 1 is separate from the SCSI bus 2, which has the 2940 and the Cheetahs for PT files. Works great.