Don't buy the Megan header! They put an extra egt/02 bung on one of the 4 runners, which looks stupid, serves no purpose, and provides an extremely obnoxious whistling noise at WOT that will have you constantly wondering if you have an exhaust leak. I have talked to no less than 3 other accord owners who have experienced this same exact problem that started only after the megan header. Also their stainless isn't quality, not surprising for the price. It starts to turn cool colors then just goes brown.
For me personally, I will never spend primo money on a header if the Accord stays a street car and that's for one reason. Where the downpipe wraps around the oil pan is the lowest (closest to the ground) point on my car. Potholes, nasty driveways, random ice chunks, life happens. The two times I've switched the header and inspected the old ones the have been bashed in right around the 2-1 merge. And my car is lower than ever now.
I've got an OBX ceramic 4-2-1 now and I'm happy with it. Not the prettiest welds you ever saw, but the ceramic coating has held up decently in the first 6 months, fit is good, and it does the job for a fair price.
The first guys who put in a header on my car were slick and managed to wrap the o2 sensor wire around the back of the block so I never have to worry about the extension wire. This wire comes with the DC Sports and is generally not included with all the others. So look into that because you have to have the right kind or wire with the right resistance.