LC Low Pass Output Filters for Inverters
You ought to consider an RLC low pass filter so that the switching frequency is significantly reduced at your output. You need to set the output filter cut-off frequency at least 30% greater than 60Hz also - this is to avoid catastrophic resonance if the filter frequency starts to coincide with the 60Hz.

You also need to "govern" the Q of the circuit when an output load is not connected - this is what the resistor does: -



The value of R needs to be chosen so that you don't get significant voltage peaking at 60Hz. With a 25mH inductor and a 150uF non-polarized capacitance you'll get a cut-off frequency of 82Hz. To prevent significant peaking you'll need a resistance of no-more-than 18 ohms but don't go too low or the peaking could cause you problems.

Given all this information you can decide whether this method is suitable. Here is the site I used for the RLC calculation with a damping ratio of 0.707.