I still have stock headers on my alti.. not much money these days, hehe. But ebay offers pretty inexpensive headers, usually with warranties. THe most common brand i see on there is OBX racing, which from what i heard does the job.. Of course, if you want to buy one of the big boys such as GReddy, i personally dont know of any major performance differences b/w the big boys and the ebay boys
. Only difference to me is the several hundred bux b/w prices!