bre's dad

hello all, new to the Jeep world and have some concerns about a Grand Cherokee I'm considering buying. Long story short, its a '98 Limited w/ quadratrac full time 4wd, 5.2 w/ 159k miles. Never offroaded and babied. Tires have less than 15k miles and while feathered a bit on the outter edges, seem to be wearing evenly. It does have some slop but I'm guessing alignment & tie rod ends. There is a lot or rumbling & road noise coming from the front, but it doesn't have mudders or tires w/ aggressive tread. There is also a little bit of a whining noise at low speed, mainly noticible when taking off/stopping. Would the whine be normal for the full time 4wd? I'm trying to arrange a visit to a mechanic for it but would like some advice on this from someone more knowledgable than me. My point of reference is from an Explorer this will be replacing and a '99 Durango a friend has. I'd really like to take the GC off my friend's hands but not if I'm looking at a small fortune to fix driveline problems. Shifts & drives fine otherwise. any thoughts on the issue or is just how they are?