4-1 header for my b16-pr3??

I bought a Da integ from a freind and it came with the jdm b16-obd-0. It also came with some dc sport headers. I was thinking about getting a better looking header like the jdm 4-1 with a 2.5 inch collector. The questions is what application do I need to get. A 90-93 ls header or a b16. I know that i will have to put both o2 sensors directly accross from each other. i also know that the b-series header flanges are the same. curious about the downpipe running underneath the oil pan.