Very silent external FireWire drive

[wasserwerk]

Yes, I know - PT9 is most exciting topic now, but I have one simple universal question.

I bought just now this one:

http://www.dsp-memory.de/v1/catalog/...ducts_id=3811&

But this drive is very loud even without disk access (idle). When this document
http://www.inxtron.com/files/article...patibility.pdf
says truth then this drive uses Hitachi HDS721010KLA330. I found one review in german magazine c't and it writes: 1.4 sone in idle and 2.5 sone at access. This are horrible values! What external realy quiet FireWire hard drive could you recommend?

I tend now to buy empty enclosure like this:

http://www.dsp-memory.de/v1/catalog/...ucts_id=10370&
http://www.dsp-memory.de/v1/catalog/...ucts_id=10830&

and separately a silent hard disc.

Second question - must it be realy a 7200 rpm hard disk - as recommended by Avid? There are many 2.5" hard discs at 5400 rpm which are comparable fast to 3.5" @ 7200 rpm (transfer rate and access time) and these are quieter. Can I use such 2.5" @5400 rpm for tracking in PT?