I'll share what we did - I have an 16 SR5 and while I really liked the rig there were some things that needed to be corrected.
I noticed that the combo of grabby brakes and soft front suspension made for some pretty good nose dive when braking. I also disliked the weak acceleration curve, pushing a lot of pedal for not much go. The designed for MPG acceleration curve is weak at 50% pedal depression your getting like 30% (just a guess) available power. The result is it makes the rig feel sluggish.
So we opted for 3 things that improved the rig considerably, new pads, 3" suspension lift and a sprint booster.
1. Akebono Premium Pads made the brakes much easier to modulate. Can be found at any Napa.
2. We opted for a Toytech Boss suspension lift with UCA's for proper alignment. Rolls on 285/17's with no rub. No more nose dive either, its stiffer then stock but is also more plush on the rough stuff. You can roll over rough ground much faster with out upsetting the ride. I'd purchase Toytech again.
3. Sprint Booster is a plug and play wiring harness that alters the throttle curve. So when you depress 50% of the pedal you get 50% of the available power. It can be turned on/off at the touch of a button. Some peps don't care about the weak feel at the pedal. But this mod makes a huge difference in the driving characteristics. Pedal Commander makes a competing product. These devices don't add anything extra they just change the throttle curve so its a more linear ramp up from stop to wide open throttle. Versus the stock curve that is very flat and then sharply increases at the end of the pedal push/hockey stick curve.
We've put a lot of miles on and offroad on this rig and the improvement to driving enjoyment is huge. Always like driving this rig. These 3 mods are one's I would do again in a heartbeat.
We did some other mods that are def not necessary but were added for a once in a lifetime chance to do some serious camping, like the CVT Tent which we like for it's awesome mattress and it's fun. They are pricey but we figured it was worth it and put over 100 nights in it the last 2 years. We like it for dry weather camping, not that it's not water proof , it is. But rather in the Pac NW you can be hard pressed sometimes to find a dry spell to dry out the canvas tent you had to pack up wet.
We also did a K9 full length alum rack. Was gonna buy a Gobi, but 6 month wait time was a no for me. Glad it worked out that way. Alum will not rust like powder coated steel and the T-slot channels in the rack slats means you can add tons things very easily. We needed the rack for the tent and it's held about 250 lbs of tent/gear all over the west, Colorado jeep trails, Moab slick rock etc. That's a lot of weight to be rocking back and forth off road and the rack hasn't budged at all.
Lastly while not necessary I do like having it a lot - and that's my hidden winch mount. Bought a hidden winch plate paired with a Warn 10k winch and I use it. I've used it for 8 or 9 pulls in just the last 3 weeks checking trail to see when the snow has melted enough to reach some mountain lakes. Very nice to have it when you need it.
There's a lot of 4Runner specific info to be had at T4R.org Super capable trucks, tons after market support and fun to drive. Enjoy your new rig.
