Okay anyway, since someone dumped a working hdds.bin in September you can hack any drive (with enough space) into an 'official 320gb xbox drive' with a bit of trickery using HDDHACKR.
This is the most user friendly guide which works with the listed western digital drives: clickie.
I'm sure there's guides out there for other makes but my googlefu is weak today and anyone interested can find it themselves.
Should be able to find an official hdds.bin from xbins.org. Careful not to brick y0 drive.