Ditto on the Durango. I have an 01 and couldn't be happier. You can pick up a 2wd 01-02 in your price range with similar miles. (possibly lower)
In a GC I think you'd be looking at the inline 6 cyl in that price range - the 6 cyl is a VERY reliable engine, Jeep has used it in a lot of vehicles for a long time, easy to work on, runs forever.
If you want a V8, the Durango and Jeep will be very similar mechnically. You can get the Durango with the "technologically superior" 4.7 liter new V8 (used in the Jeeps) or the "old and dumb" 5.9 liter. I have the 5.9 and am very happy with it - I get 17 mpg on the highway which is fine, since I have a short commute. Again, it's an engine anyone can work on. The durango has generally heavier-duty components than the GC. (but then again it's a bigger, heavier vehicle)
The Durango is available with 3 rows of seating, is comfortable, has plenty of power, lots of cargo space with the rear seats all folded down. (significantly more than my dad's GC) I think of the GC more as a large car, whereas the Durango definitely feels more like a truck to me. I definitely feel safe in the Durango, it's a pretty large heavy chunk of steel.
I wouldn't count on either the Durango or Jeep to be reliable as a whole, but that's why they are cheap used. I bought mine with 28k miles and now have 40k miles and have basically had no problems with it. I paid a little over $15k for it last year and it still had about 6 months of warranty left when I got it. (SLT+ model with the 5.9, 3rd row, leather seats, rear air - i.e. loaded - the sticker on mine was probably around $33k)
Edit: on the engines, the Durangos were only available with V8s, the 4.7 was the standard and the 5.9 was an option on the SLT and standard on the R/T (top of the line) models. The 5.9 has a slight performance edge and as I mentioned has the advantage in that it is a much simpler engine - but the 4.7 is the "new" v8 that chrysler is putting into everything. The 5.9 was their performance engine before the Hemi came out.