Lacie makes a great enclosure, but you never know wich HD is inside. I've seen Lacie d2s with Maxtor, Samsung and Seagate. Their product is covered by a 1 year warranty.
Mercury Elite Pro Aluminum units are mounted with the latest Seagate drives. The unit is covered by a 2 year warranty PLUS 3 year warranty for the drive, directly from Seagate (the drive itself is covered by a 5 year warranty). I don't think you'll find a better deal than this, and they cost about the same.
Check it out:
http://eshop.macsales.com/shop/firewire/1394/USB/EliteAL/800+USB2/
The 320GB unit is the best in terms of cost/GB (in this price range).