How many hardware PWM pins and ADC on the ATxmega128A1?
There are external I/O expanders with PWM.
PCA9671 for example, has an I2C interface.
OpenServo.  It's an aftermarket retrofit board for a commercial R/C servo, which accepts commands via I2C.  (available on sparkfun)

P.S.  It's not an uncommon misconception that a hobby servos really require hardware PWM on μC side.  Servos need to be updated with a pulse every 20ms.  A whole lot of servos can be updated from a single timer interrupt service routine (ISR).