I always look at these things with the, Do you value the car, do you want it done right ?
If you answer either of those with a yes, don't buy a crap turbo kit off Ebay. If it means waiting a few more months to save the extra, get a reputable company to fit a known and trusted set up. If it ain't done right, best case scenario is it will be low numbers. Worst case, it self destructs at the first sign of a dyno pull.