It really depends on what you want your vehicle to do when you look at modifications. Just jumping to a solution that has not been matched to a "problem" seldom leads to the best results.
My experience with friends that did it all; building engines, drag racing, etc. was to look at the basics first. The most basic is reducing the energy needed to overcome the inertia of the vehicle. so look for areas where you can reduce the weight of the vehicle, and also look for things to do to get air flow going past it better.
An engine is essentially ab air pump. Focus on moving that air as efficiently as possible, which is a straight line. Once you straighten out the intake and exhaust, you can then start looking at other things.but again it really depends on what you want. If getting off the line quick but not worried about top end speed, that is one set of upgrades. If you're looking for more top end speed but not as worried about how fast you get there that's another. If you want better fuel mileage, that's another set of upgrades. I ran a 6 cylinder in one of my Rams and was very happy with the performance. I did a few things including putting a smooth front bumper on, redirected air with a lower valence, put a cat-back exhaust on and a better straighter intake, and made sure I wasn't lugging around hitches and other things that I didn't need. Never tuned the engine but made sure I always kept the air filter clean and just general maintenance.
Good luck