I would recommend going with one of the eBay headers. I'd get the cheapest one you can find, because they're all pretty much the same (and likely made at the same factory). I don't think anyone stateside produces a header for the GA anymore. Many members on here (myself included) use eBay headers on our SR20s. All you need to do is purchase high quality steel or copper gaskets to replace the ones that come with the header.