Hello Carole,
posting my exact model won't get you very far, as the model is probably not longer available as such .... this means if you do see a LaCie d2 burner it will be a newer model - LaCie seems to name them all alike.
Also: LaCie is not a manufacturer of burners, but an assembler. My burner houses a NEC 2500-A, others have Pioneer ingredients I think. You have to dig real deep to find the "real" specs.
Most of the burners on the site you mentioned are USB 2, which I wouldnt recommend. The most interesting is the gray Sony - IMHO.
Add-on: Just went to the LaCie website and it seems that all their new burners are Lightscribe (a labeling method) - so if you don't need that you're spending money for nothing.
Maybe this is helpful:
http://external-dvd-burner-review.toptenreviews.com/
hope this helps
mish