Exactly which pipe do you plan on installing? FMF makes two pipe for 95 to 01 KDXs. FMF IDs the KG-35 as the woods/torque pipe for the 200 and the KG-30 as the woods/torque for the 220 and the rev. for the 200.
With porting, larger carb etc it looks like you are looking for more power everywhere including mid to top end power. I don't know what kind of power delivery you're looking for but if your intention is to add power everywhere including higher rpms you'll want to be sure your dealer has ordered a KG-30. There is often confusion between the two because of the way they are identified. Though the KG-35 works great on the 200, which it was originally designed for, it does little for the 220 at higher rpms. The KG-35 works well on the 220 if you are in really tight condition where you're mostly running in 3rd gear of lower but if you find you do much riding over about ½ throttle or in open areas the KG-30 is often the preferred choice. The KG-35 certainly boost the bottom to mid power for he 220 but offers little gain over the stock pipe at higher rpm hence FMF reason for only list one pipe for the 220, the KG-30.
Once you've decided which pipe best meets you riding style, conditions etc be sure you order the pipe by its model number and not by its name to avoid any confusion.
Once we know which of the two pipe's you are installing we’ll be able to come up with a reasonable starting point for your jetting.
David