research.
there is a ton of info out there on forums and retailers websites on options and how to do it.
Pirate4x4.Com - The largest off roading website in the world. has a HUGE resource of info and knowledge- join and spend a TON of time searching and reading. I have ben a member there for over 10 years and have built a few rigs but hardly ever need to post there, its all been done
Why do it is also a question you should have an answer to. You sound like your set on it? Why? Rockcrawling? perfect. Desert speedruns? Stick to building your IFS.
Get a good idea as to how you want to play with your Toy and what will serve you best. I LOVE straight axle wheeling, if the rig is set up correctly, for most every situation. IF you go with a link setup, they are infinitely tuneable- leafsprings are slightly tuneable. IFS typically is better for high speeds and road travel, but again, can be used everywhere effectively. Your choice, no one can make it for you.
Your '94 is a great SAS platform and will take a leafspring setup in front VERY easily. Cut of all IFS bracketry, setup rear shackle hanger sleeves using the jigs most companies have, add the front spring hanger- and youve got leafs. Setup your front axle, steering, driveline- done.
Its not that easy and i left out a ton of steps and choices for you to make along the way- but that is all that it takes. If you have a welder, torch/plasma, grinder, $$, and know how to use them, it is an easy project.
throw out a little more info for us and we might be able to help you better.
Why. Budget. Skills. Help. Resources.