Plenty of People on the forum have gone the turbo route with N/A and Factory turbo Motors with good results. you could source an l28et or just buy bits at a time and put the motor together when you finally have everything needed to put it together, the mater of cost is really kind of tricky, for instance I bought a complete l28et long block with fuel injectors, turbo distributor ect... for $700 bucks, still wasn't everything i needed but it worked for me at the time. MY good friend on the other hand got a smoking deal on a custom manifold/turbo and intake setup for about 400 bucks to put on the motor in his car now,different route, same goal.you're gonna have to plan a budget you can work with and scour the forums for sale thread,Ebay,craigslist,Junk yards, Garage sales, anywhere really, you'd be surprised with the stuff you can get if you know where to look. google Hybridz then L28et into 240/260/280 and or L28 n/a to turbo conversion and you should get some good results if you can't find anything using the Hybridz search.