Too much going on and unanswered from your part. Big one, what age vehicle are you looking for?
Here are key things that I look for:
Locking differential, or limited slip
Skid plate, even though it feels like it just puts your mind at ease and doesn't really protect much
4x4 of course
Extended range gas tank
Now theres a bunch of other options a guy can look at for other things, towing, bed size, etc., but you didn't ask for anything else. Even that small list will eliminate ram imo. You can get those features sometimes but when I've looked for trucks ram is the hardest to find those basic things.