all depends what power you want IMO, if only around 200bhp, you may as well keep Ke-Jet, but for big power go for cossie management, the looms are interchangeable with only a small mod needed for the
TPS depending whether you go for L6 or L8, L8 is the better option, then you can use the 3 bar map sensor and have the car live mapped for ultimate driveability