Yea really the only thing besides turbos, superchargers, or swaps that's going to give you any noticeable gain is reground cams, like Deltas. However, I have heard that the power gain is not as noticeable on EJ22s as it is on EJ25s. I'm not sure if that's true; I, for one, love the 1500 regrinds on my EJ25. For your car, an EJ25 swap with reground cams is really the best for your money...but given that you're asking about eBay chips, I'm guessing engine swaps are a bit beyond you. I don't mean to offend you, but it's what it is.