a quick update and review of NoiseMagic's NoVibes III:
ordered late night on Saturday from FrozenCPU.com, and received on Monday afternoon. i was kind of shocked, cuz the company's in NY and i'm in LA. it took Apple 2 days to deliver a MacPro with NextDay delivery from Fullerton (30min from my house). so far, so good.
installed my SCSI in the NoVibes. the screws don't go in all the way, seems like the extra black paint on NoVibes is not allowing it, and it's starting to strip the screws. at least the NoVibes sits very tightly in the optical drive bay (actually, so tight that i prob don't even need screws), so i have most of screws go in half way. it's all tight fit, which in my book is good for reducing noise. connected all cables np.
started up MP. dayum. no more hums. SilentPCReview.com is absolutely right. the improvement is very very very dramatic.
i still get a bit of "sssssssss" whirring noise, since the optical drive bay is in front, near the grill.. but it's not that bad. if i cover the grill with my hand, the hiss is reduced, so i'll prob think of some thing to put where the grill is, without restricting too much airflow (like a few layers of dryer sheet, etc.)
the current whirl hiss i can live with for now; the important thing is i can use my SCSI drive internally again without excessive, annoying noise or hum.
thanks again for all who posted.