Ok I'd like to add some fuel to this fire.

In your 2wd F150 you really won't go far off road (you've already learned this). In a 4wd Toyota of any year model you'll go farther. Toyotas are what I like to think of as modern International Harvester Scout II's, they'll go damn near anywhere stock.

If you do want to upgrade the Yota my recommendations are these.

1) Decide how "big" you want to go.
2) Good tires will take you a long way.
3) Learning how the rig responds in certain situations (aka driving experience) will take you farther.
4) Lockers make a Yota a tank on the trail and are well worth the money.

I run an Aussie in the rear of my 89 4runner and a Lockrite up front and it goes where ever I want it to on 31 inch almost bald tires.

Decide what size tires you want to run, sounds like you want 33's, and get the rig geared for those tires (4:88's) and drive it with the new tires and gears. If you find that you're getting stuck due to lifting a tire then look at a locker.

My advice is get the rig where you want it, get tires that you want, gear for those tires and wheel it. You'll be surprised how far you can go on open diffs in a Yota. Don't lock both ends at the same time. If you need a locker plant one in the rear and drive it for a few months that way you learn what it can and can't do. Learning your rig is way more important and less expensive than throwing a couple of lockers in there and going nuts.

Just my couple of pennies.