I too have never heard of it. Where all are you looking for a header? You are looking for 94-98 GSR right, not 99-01?
Any B series is going to fit. This one is off a 00 ITR. My buddy rocked one his LS and said it was decent.Air mass? It was like an old sub brand of Holley. I had one of their exhausts called the Thundermuff It was decent quality.
He's selling it for $50.