It really depends on how much extra power you want.  The Magnuson option boosts your 4Runners engine to around 390 at the crank on 6 psi of boost, and you really do not want to go further than that on a completely stock engine. If you install the supercharger, consider adding a bigger radiator to deal with the heat.  Magnuson already includes an intercooler in their 4Runner supercharger kit, but more cooling capacity never hurt.