the-rebel-agent:
You can buy the same one here:
http://www.ebay.com/itm/160806790230?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649and I do believe this library will work with both.
The only difference is the chip packaging. (DIP 16 and SOP 20) There are no functional difference between two sub-models. So the-rebel-agent's library should work perfectly with both the types. If you need more details on the difference of the package (I don't think you need :P) you can find it on http://letsmakerobots.com/files/WTV020_manual_V1.3.pdf