Hey Rolando, and welcome to TRS!
I love this site, and it's taught me a lot over the years. There's quite a few things you could do, and locking is one good option. For daily driving, it depends on what your stock gear ratio is for best fuel economy, but with the 31's, I would go with a 4.10 gear. A lot of people fear the gear, and fuel economy in this case will hardly change. If anything, you'll get up to speed in city traffic a lot easier and help improve in city driving & towing.
The 3.0L is said by many that it is durable & reliable, and gets average mpg, but can also lack the grunt when you really want it. A common swap is the 4.0L OHV for more useable power.
You can piece together lifts, and a body lift is good for running a larger tire if you choose that route, and you can do a "spacer lift" under your front coils for about a 2" lift using large diameter steel washers. I did it on my last Ranger, and it worked great. What normally would give lift actually just help "unsag" my front end from years of abuse. There's a Tech Article in the Library about doing that. But, you're a certified tech, and I'm sure you know your way around a truck.