Glad to see you didn't take my post to heart like some other people do on the boards and yes, I agree that there is a lot SHI* flying around on the board these days.
Somehow I knoew you were looking into a turbo since you had "Spoolin" in you user name. 10-12 PSI won't be unsafe if you running stand alone engine management "and higher octane gas". I'd run lower PSI personally, lke 7-9. But that's me, I'd just want to make sure the motor can handle 10-12 before I boost away. Just look into rods and pistons in the near future and you'll be ok. Rods are what usually goes when the engine blows. You could always just have them heat treated and shotpeened. If I'm thinking right, being that our compression is what it is and depending on the size of the turbo, at 10 PSI on a 2.0 ltr we should be able to reach 210-220 hp. This is of course assuming that the fuel is there to support 10PSI.
I have a question though, what kind of turbo is it? Used, new, Garrett, Mitsubishi, IHI? $250 is mighty cheap for a turbo, for the ones I had been looking at like IHI AX53B60, GReddy TD05, or just buying Subywans stock WRX turbo would cost me $500 at the least, on a good day. Oh in case you'r wondering the IHI AX turbo I'm talking about is the one used in the APEXi Civic SOHC turbo kit
Also, is the intercooler custom and is the price you're giving including the end tanks with the intercooler or is it just the core alone? What size injector were they planning on having you run? Good luck bro