best way to learn, i learnt by building a ute with my old man from ground up. was the best learning experience id ever had!!
Dont know enough about the diff bolts and studs, someone else may know more...
If your ute is still running front drums, it shouldnt be too hard to find a set of disc front struts somewhere going cheap enough.
I do know many people choose to go with 120y struts, i believe the shock tube diameter is the same, however the stub axle is much larger allowing you to run bigger brakes. Chuck a decent set of shocks in them ie. konis..... haha maybe a little pricey but worth it! Check it all out in the tech wiki...
otherwise, upgrade your front sway bar, and throw a 120y one in, you go from i think its a std 17mm 1200 sway bar to a 20mm, so far ive heard nothing but compliments of the noticeable difference it makes to your everyday handling.