Hi, jakshale, and welcome to Apple Discussions. Your Serial ATA (SATA) enclosure isn't what you need, as you've guessed; your drive is a Parallel ATA (PATA, also called IDE) unit and needs an enclosure designed for that interface. Any enclosure intended for 2.5" ATA/IDE/PATA notebook drives will work. Here's one that's almost as dirt cheap as the one you bought:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817106093
Note that if you intend to use the newly-repackaged drive with a Powerbook, a USB-only enclosure isn't a good choice unless you get one that can use its own AC adapter. This is because most Powerbooks don't supply enough power through their USB ports to power an external drive. The same Powerbooks
do supply sufficient power through their FireWire ports, so an enclosure that can be connected via FireWire is a better choice. If you're going to use the drive with a desktop Mac or an Intel MacBook instead of a Powerbook, a USB enclosure should be fine.