Troy,

The 9254 is a standard size servo and the 9257 is a mini servo. I think the 9257 is around $50 and the same for the 9650. Towerhobbies probably doesn't have it. Try looking at helidirect or readyheli. They are two of my favorite places to shop for heli parts.

The chineese weight mod just adds weight to the tail grips, so it is easier for the servo to move the grips at operating speeds and it keeps the tail grips from rotating back in forth during flight without rudder input. Helifreak has some threads on it.

Nick