You will need 2000 watt inverter to work properly and handle the loads, with a 500 watt you will either trip breaker or circuit if you put one in line or you will burn it up one of the two, agree with Ozz not big enough.
Try this web site will
http://www.theinverterstore.com/?gcl...FQfxgAodIDhHRg give you tons of info on them plus help you size for what you are doing.