I use a 2008 Toyota 4Runner limited V8. It has full time 4wd, and 4lo. I added a 2nd aux trans cooler... Just for security. It already had a factory aux trans cooler, but I kept that AND added another one.
I put on fj cruiser coil springs and Bilstein 5100 shocks which give it a 2 inch lift, and actually IMPROVED the ride. It's rated to tow 5k lbs. I also put air ride booster bags inside the rear coil springs so that I can level it out when towing with a full load. Tows great. Rides great. Mileage sucks.. I always seem to get about 10 mpg, whether towing or not... But I do have a heavy foot, and when I tow I'm often going 70 to 80 mph. Every summer I take a 600 mile trip each way pulling a boat, and the truck does fine. I put a Bluetooth device in the odbc Ii port that lets me monitor trans temp. The 2nd aux cooler lowers temps by about another 30 degrees which matters on 90 degree days going up long inclines or in stop and go traffic. I wouldn't want to do that trip without it. You can buy a Hayden cooler in a kit for under a hundred bucks, and install it yourself. Keep your trans cool, and it'll last even with towing.
It has a 5 speed auto, but put it in 4 instead of D when towing.
I previously had an 04 sr5 4runner with the v6 and factoru suspension, and it didn't tow as well it often started to sway at 60 to 65 mph.
So I usually had to keep it at 55 and then I was fine. Get the V8 to tow.
I paid 21k for my 4runner about 4 years ago with about 120k miles on her... Then I dropped another 5k on tires, complete new brakes including stainless steel lines and the air ride boosters, new coil springs Biilstein shocks, new sway bar end links and polyurethane bushings. ... It was a lot of cash, but the ride is sweet! Smooth, powerful, reliable. I can't complain. If you get one there a few things to look out for. Like all vehicles it has a few known weak spots. One big one, is if you start it up on a cold day and hear what sounds like a vacuum cleaner running for 30 seconds or so... Look out! It's got some special anti smog thing that kicks in only when it's below 40 degrees or something, and if you hear that sound, it means some Valve related to it is starting to fail. The bad news... If it does fail. It's 4k at the dealer (mostly labor) to get it fixed.
The good news, I went to a 4runner enthusiasts site and googled the issue the first time it happened. Some guy posted specs for a bypass of the system, and sold premade kits for about $50. I put it in and I'm good. On cold days, instead of that pump running, a relay sends the current through a resistor...this makes the truck think the pump is running -- so it doesn't throw an error code, even though it really isn't running. You need the relay and resistor to make the truck think everything is working properly, otherwise the truck will throw error codes. Problem solved, and I avoided a $4k repair! (which would have sucked!l
2 other issues. First, brake calipers sometimes sieze. I think the pistons and the caliper bodies are different metals. It sucks, but changing them out when needed goes with the turf.
One was siezed when I got my truck, but I swapped out all 4 as part of an upgrade to the beefier brakes from the 2010 to 2015 4runner -- it's a bolt-on upgrade with no modifications needed, and I have been good for 4 or 5 yrs now. You won't know it siezed unless and until you do a brake job, but seized pistons wear your pads out faster and cause them to wear unevenly.
Other issue is that some of the frames rust from the inside out. It's the same frame used on the Tacoma, a Toyota did a 10 or 15 yr voluntary replacement on frames that failed, but didn't include the 4rumner. My truck was a Florida car with zero rust, so it's not an issue... Plus I bought 4 cans of a special treatment to spay inside the frame, but uli haven't done it yet! Anyway, long post... but I thought I'd list the good and the bad. Overall, I love the 4runner, and hope to have her for another decade if not longer.