High-current capable, high precision sine wave
I am not sure what your output stage looks like, but if its a half bridge then you just need the filter on the single output.  If its a full-bridge then you need a filter going between each of the two half bridges.

I would recommend delta-sigma modulation rather than PWM.  PWM tends to require that the timer frequency is much higher than the output waveform frequency.

For example if you want to make a 50kHz sine wave with 8-bit pulse width resolution and you want to have at least 16 pulses per sine-wave at 50KHz then your timer frequency would need to be 50kHz * 2^8 * 16 = 204.8Mhz.

To achieve the same amount or better of output ripple using delta-sigma you would only need a timer resolution of 50kHz * 2 * 16 = 1.6MHz.

Additionally, you can perform both PWM and delta-sigma open-loop so that your ADC does not become a bottleneck.

delta-sigma is pretty easy to implement open-loop.
keep an internal state variable V.
calculate the desired state V_ref = sin(t) + offset at each point t.

if V &lt; V_ref then 
  set ouput transistors to high for that time slice
  V = V + dV
else
  V = V - dV
  set output transistor to low for that time slice
end if

The time slices are fixed, say 1us or so.

I have implemented the delta-sigma logic described above on a 600W sine-wave generator and it worked very well.