e38 Hound! Good choice man! I'm definitly biased, but I absolutely love my car! ... I could go into a year by year rundown of the changes and such ... but here are a couple links that already contain that type of information.
Sport packages are pretty easy to find as they were a very popular option. But I don't think the sport package was available until '99. And, the sport package only became available on the long wheel base models in '01. Also, the sport seats are only available on the short wheel base model (740i) ... and they are sweet! Those seats are the only reason I went with the i, instead of the iL.
Good luck with the search! Just keep checking autotrader ... you'll find some gems there every once in a while ... but they will go pretty fast.