Here's a couple of Ebay links to order the coils
at the best price that I have seen so far($29.99 each).

Here's the Ebay link for the 12" coils....
12 inch


Here's the Ebay link for the 14" version....
14 inch

I would recommend the 14 inch coils in the lightest 100 pounds/inch
rating for most folks.  In a sagging Runner, it should give close to 3"
of lift and a soft ride. Flex should be the same or better than before. The
leafpacks will probably last another 10 years now.

Using heavier rated 14" coils 150 pounds/inch should yield about 3.5"
of lift as well as even more payload ability. Ride quality is still good.

The 14 inch coils will not fall out when it is flexed out to the
max( with the factory leafpacks). The stock Runner set-up perfectly
limits the extension to work with 14 inch coils. The shorter 12"
coils might loosen up when flexed but probably enough only to rattle
but not enough to fall out. 

Regarding the 4 mounts for the 2 coils...to reduce costs and save the hassle
of welding mounts in place, it's just plain easier and pretty cool to use
the lower rubber snubbers as the bottom locators...and to cut about half the 
upper steel stoppers off to act as the upper locator mount. So simple yet so 
effective. A torch can be used to cut it but that's a bit messy looking....mask
of with some tape and use a 4" cutting wheel to make clean cuts. I have 2 or 3
links on folks that have done this similar thing. ZUK
     Weldless mounting
     Another no weld set-up