There are lots of opinions; however, I'll go with the Team Green set-up:
Pro-Circuit/KYB works fork kit. PERIOD. Once you've ridden 'em-you'll know.
Pro-Circuit/KYB bladder kit - shock revalve. Same as the forks.
Pro-Circuit "Dog-Bones" and fresh bearings for the linkage.
Of-course, this implies a few $ spent at P/C and havin' it all done for you. I can't tell you how many of my friends have ridden my bikes and gotten reallllly upset at their "late model super thumper Hi-tech mega alloy" scooters. Especially the guys with the $8K KTMs!
I've yet to see a Race Tech "Gold Valved", Works Connection or any other companies set-up work as well as P/C's. It helps to remember how involved Mitch and the Pro-Circuit guys are/have been with KMC's racing program. Also, what after market company was making parts for the SR500's (Works KX500's ala KHI, Japan...) back in the days of the 500 Nat's? Hmmmmmm?
Pipe and motor mod's of your choice...a fly-wheel weight can actually help on some of the older (pre-94) ignitions/rotors. It's a matter of how you "brake and clutch". Once again, I run P/C complete engine...especially for MX.
If you're seriouse about your racing and are of average size (5'6" - 5'11") I recm'd a low sraight bend handlebar (RM low) and adjustable/quick clutch perch (really inexpensive set-up from Malcolm Smith-<$20!) and probably a BRP bar clamp kit. This set-up makes your bike feel tighter/lighter.
Make sure you set your sag(s) correctly. Also, there's a lot to be gained by adjusting the front fork in the triples. With these mod's you'll think you've put your motor in a 250 chassis.
What's really important is this: Be honest with the guys that do your suspension. They're going to give you what you ask for...so don't say,"I wan't it to be just like Bubba's bike..."
Do you really plan to do 110' doubles at Anaheim?
Manny
