A good MX have this mods....But tons of money...
Good set of A-Arms +2+1 LT or not..
Durablue,RPM or Lsr axle
Shortened swingarm -1 or -2 with Double Bearing Carrier
Good set of front shocks and rear shock
Torque mods on the motor (2 in 1 carbs,milled head or coolhead 20cc,MX porting)
Good set of pipes ->your pro circuit are good
4 Klaw MX or Holeshot MX Razr MX 3 good MX tires
With that mods your are in good way