Check out what Jim is selling here.
Parts in the top right corner, or here...
http://www.jamesoaksenterprises.com/
Lots of people do body lifts for bigger tires, but 31s will fit with only 2" of lift. If you go with bigger tires than that, your front axle wont last long. A cheap 4" lift is only about $500, or you could piece one together via the internet, junkyard, and classifieds on this site and elsewhere.
The front you need pivot brackets, either drop brackets for rad. arms, or extended radius arms (extended is more expensive, but gives better wheel articulation.) coil springs and shocks, and a drop pitman arm. Perhaps longer brake lines too. I just picked up drop brackets from the classifieds on this site for $135, still searching for a pitman arm, might end up buying a new one...
For the back, you have some options. Blocks, Add-a-leafs, new leaf springs, new shackles, or a mixture of these. I am going with Explorer leaf springs ($20 each from jy) and 2" lift blocks (free, jy. Yours may charge. 4x4 Rangers came with blocks.) and hoping for 3-4" of lift over my old tired Bronco II springs, but it may only gain me 2.5".. If that is not enough, I will add belltech 6400 shackles for an additional 2", and if I end up doing a 6" lift up front I might get some add-a-leafs for the Explorer springs.
http://www.summitracing.com/parts/BEL-6400/
http://www.summitracing.com/parts/SLF-2325/
http://www.summitracing.com/parts/EXP-13120/
http://www.summitracing.com/parts/SLF-1109/