From the sounds of it, you need to remain where you are and perhaps look for a heat exchanger/intercooler for your CTSC. I mean no offense when I say this, but if you are balking about spending the money for a proven turbo kit (i.e. SoS, LoveFab, or what have you), then you have no earthly idea what you are getting into with the horse power numbers you are wanting. I could be wrong, but drivetrain loss will equate to somewhere around 50'ish hp; therefore, to reach your desired number you will have to push anywhere from 450 to 470 hp. Things CAN and WILL break at these numbers.
As others have said already, you will need a good catback 2 1/2" diameter or more, some high-flow cats, an FIC since you need to remain SMOG compliant, and of course have your car tuned. This will cost you several thousand dollars on-top of what you spend. This does not include a clutch, so hopefully you have a good one already.
There are cars running these numbers reliably, but it remains a gamble no matter how you look at it. If you really sit down and think about this, you are already making sacrifices with quality and proven reliability because you cannot justify the money needed to get the car where you want it to be. These cars are not american muscle where hp can be found cheaply. You are going to need to spend some serious money to when things go wrong, so hopefully you have figured that into your thought process.
Good luck in whatever you decide, but I would strongly recommend that you consider what others have told you.
. I'm just looking for a little more pep and stronger performance. From what it sounds like a simple turbo set up will get me there.
