I'm in the same boat so to speak. Still deciding what I really NEED and what I can add on later. Leaning toward a 07 Limited now, after starting with an 02. Here's a link you might like for all the packages, options, and such. I've found it very useful for comparing changes and packages from year to year:
http://consumerguideauto.howstuffworks.com/2003-jeep-liberty-2.htm
That's perfect - EXACTLY what I was looking for to break the packages down...got some more reading to do!