Depends on what kind of power you want to make. Turbo power comes on very fast, s/c is more progressive, building with rpms and,IMO is more streetable. An analogy would be a supercharger is like a sling shot or catapult and a turbo is like a cannon. Both are money pits and, if you are really serious about FI, don't rush into it. Read everything on this forum (FI), Internal Engine and External Engine, ask questions when there is something you don't understand, and once you have a pretty good understanding, formulate a plan, spec your motor out, search for and buy the parts you know will work well together and compliment each other, or buy a package that already has all or most of the pieces you want and build on that. You can also just buy a used kit and slap it on your existing motor and it will make a certain amount of power, but not as much as if you plan it all out; you will get out of it what you put into it. A stock motor making 500-550 rwhp will be at its limitation, IMO. If you do this, start saving your money for a new bottom end.
Tom