How did you do the leather? That is on my list too.
I got the "leather" replacement from eBay. It was actually a lot more simple than I thought. 4 Bolts and two plugs and you can pull the seat out. From there just flip it upside down and un-clip everything. Things went faster when I realized that the circle clips go in easier if attached to the seat cover first then to the seat instead of the other way around. All in all only took about 2 hours.
Here is the link for the seat covers I got. They look exactly like real leather and a Vast improvement to the ripped and cracked seat covers I had.
2001-2004 TOYOTA SEQUOIA Toyota Tundra Passenger Bottom All Synthetic Leather Seat Cover Gray. This Bottom Seat cover, built to factory specs with OEM Quality Material to match the Interior of your vehicle!
I tried some of the arm rest covers that just slip over the factory ones and they are super loose. I'm going to figure out a better solution for those too.