Personally i would go for a mongoose 2.5 inch bore system with either a 3,3.5 or 4 inch outward rolled tail good for a few extra horses, as for tubular manifolds auto specialists do them but there isnt much power gain not sure who else does them i think area 6 (ian howell) used to do them but unsure now, chip wise go for an ahmed bayjoo or turbosystems chip both very good imo not sure about anti-lag but am sure someone will answer that shortly