l Want To Turbo It With A Stock WRX or STi Turbo, Does Anyone Know The Procedure?

Turbo-ing an N/A car is a p.i.t.a. but possible. What would be more reliable is just doing a ej20 or ej25 swap into an RS. If you still wanna go through with it though go here http://rs25.com/forums/showthread.php?t=3541

You will probably need to upgrade ur fuel pump & possibly injectors depending on what kind of turbo u pick. Of course l assume u already know about all the plumbing of oil lines & coolant lines associated with a trubo, & obviously u will need to modify you're exhaust to accpet a turbo. If reliablity is a concern u should really just rebuild the engine with lower compression pistons & head. High compession plus a turbo = a blown engine sooner or later.

Turboing an NA engine is more money than it is worth, u will get better results with a block that is designed for a turbo from the factory, it will be cheaper & wo not blow up on u if u make a mistake.

l would look into just doing a full motor swap, l think by the time you got the rs motor complete, getting all the piping made, oil lines, especially tuning, and then it would have been cheaper to get a motor out of a wrecked wrx, plus the internals of the wrx motor are already made to handle the boost so you will have WAY more reliablity

far cheaper and less trouble to sell the car and buy the turbo version you like