The back seat does fold down in a 60 and it should have head rests. US models do. Show us some photos of the vehicles you're looking at.
If starting from scratch I would go with the 100. Advantages of 60 are just that they look cooler and are easier to work on.
I've had the EFI 60 series...
I've had a '90 for 17 years. It doesn't see a lot of miles (about 160K now) since it's a vacation home rig but it's always been dependable. 3.0 and auto. Most attractive 4Runner body style of them all, IMO.
You would likely get a good deal on your dads' 2006 Tundra. 80 series? Over priced gas pigs prone to HG failures.
A no brainer in my opinion. Actually, I'd just keep the '94 pickup but I guess you're not considering that as an option.
Got a photo of that? I'm also curious about the Moog problem solver components that SevenFaux referred to. My '95 has just a bit over 100K miles on it now. Suspension and steering has held up fairly well, but I just run stock size tires.
You've fixed the big ticket items so no point in dumping money into an engine swap. Sounds like you're tired of it and it's time to just move into something else.
I don't have a problem with slow and would keep it.
For a daily driver and road trip truck I don't understand the urgency in lifting it. Or lifting it at all, for that matter.
Will you be carrying a lot of weight in the rear? If the sag isn't bad and you don't have plans for a great deal of weight remember that more leaves/stiffer springs...
One thing to consider is how much your springs are currently sagging. I bought 1 1/2 to 2 inch lift shackles for my TLC and they probably provided 1" at most over actual stock ride height with no adverse effects over many years.
https://www.4crawler.com/4x4/ForSale/Shackles.shtml is where I'd...
Go to IH8MUD for the most info on the 70 series LC. They have a sub forum specifically for these. I gather that the L engine is pretty much a dog with not much HP or torque for a heavy wagon. Some of them have a bad rep for blowing up too.