I have a stock 1993 Tracker and I have plans to make it into a moderate offroad truck.  I need to know what is the easiest/cheapest way to lift it and also how big of tires can i run on it?

start with coil spacers, 30" tires on your current wheels, put a lockrite in the rear and go have a blast with it.

Would you keep the engine stock, and would i need to upgrade the stock front lockers?

Depends on your budget. Skys the limit. And I would avoid the front traction aid to start.

A 93 Tracker is already a moderate offroad truck. 
I agree with JLUCK, raise it up, put bigger tires on and lockers in the rear, then enjoy it.  After using it you will find out what the next steps will need to be for your type of wheeling.

Would you keep the engine stock, and would i need to upgrade the stock front lockers?

Unless the engine is shot then i would keep it stock until you've used it a while. if you then find it lacking then think about a few mods but generally speaking for off-road use you will get more capability per dollar from suspension mods and tyres.

I did every thing i wanted to with 30" tires and GV springs. That was with open diffs and stock motor.