I bought that case in the quad interface and popped in my own Seagate 750GB drive. It has been performing flawlessly thus far.
The only draw back for me with the OWC cases - they use IDE drives instead of SATA drives in all the cases that do not have an eSATA port. It is not an issue now, but could be one down the road if you decide to put that drive into a newer computer.
The draw back with Lacie - 1) only a 1 year warranty, 2) they do not tell you what drive is inside their case, 3) they do not give you the balance of the manufacturers warranty on the drive in the case, 4) while there are quite a few Mac users that recommend them - if you start reading reviews on Lacie - they have the lowest percentage of positive (4 & 5) ratings of any hard drive reseller (except maybe Iomega)
Have heard pretty good things about the Fantom drives that Kash has pointed you to and would not be averse to one of those. If the warranty term is of issue to you, increasing the warranty to 2 yrs thru newegg will increase it's price to $174 vs the OWC drive which will still have another year on the drive plus the software they include if it is of interest to you.