I'm not sure what brands you've looked at but a few years ago I decided to buy an eBay header for my integra and was very pleased. The brand was OBX and it was awesome.. I've thought about buying a cheapy header for my fit but I don't think OBX makes one for it so I'll probably save my dollarrzz and get a real one.

Anything you you buy that fits properly is bound to beat the hell out of the stock header. I picked up a second hand Megan header with heat insulation blanket for $110... Keep your eyes open on this and other forums but be advised that there is a super moderator on another Fit Forum that is also something of a troll.