You were right about us replying with "SEARCH first then post!" but I might as well expand on that.
Yesterday there was a thread similar to yours of which you should read. Not exactly the same thing but will probably answer or clarify some things for you.
zerothread/246180
Secondly, please please PLEASE read the stickies at the top of this forum! Almost all of the questions people join to ask on their first post can be answered there. Here is the link...
zerothread/99647
Scroll down to "Turbo Tech" and check all of that.
On top of that, if you still have a question, email Brian (WDRacing) with your specific question/s. I'm sure he'll post in this thread anyhow, so you might as well just wait for it.
As for my advice, if you're completely clueless and have never done anything auto-related yourself before, you're safe with just giving a performance shop a month to custom build your turbo kit to your power goal. This is your most expensive option. On the other end of the spectrum, AKA the cheapest, you're completely DIY minded and would piece together a kit from some kind of T3 turbo with a cheap IC likely from ebay. Place yourself in that spectrum where you figure you'd belong.
About the Greddy kit, last time I checked they made an S13 kit too, or perhaps the S13 and S14 are no different. Anyway, its expensive but certainly effective and would net you your power goals, depending on how beat up your KA is...