I really wanted (still do) a KLX-SF due to the fact that the 300 barrel is a cheap upgrade and nets you about the same HP as the DRZ400 but with a lighter weight and a 6 speed
I also remember there being some other small KLX tweaks you can make, like drilling the vent hole for the crank case breather larger?
Also some carb adjustments for better response like drilling the slide, and removing a coil from the slide spring for less preload.