Your questions are all good ones but there's really no definite answer on an internet forum to any of them. Everything you get is going to be opinion based. If you're really serious about upgrading to a newer/bigger truck invest 20-30 hours or more and read through posts on various forums, shop sites for prices, check out reviews from the pros (road and track, etc.) and make a decision based on what you find.
After investing the time the decision becomes easy. You'll end up with the right truck. Wander into some dealership and buy the first thing they push on you and most likely you'll end up disappointed. 20-30 hours sounds like a lot of time but you can pretty much count on making $100 an hour or more when you consider how much a wrong decision would cost you.