Pure sine wave inverter suggestions?

As far as wire size goes, that has to do with length as well. Without knowing how far the run is from the inverter to the battery, it’s hard to say what wire size is appropriate.

Pure vs Modified used to have a lot do with price, but as cheap as the PSW’s are, I can’t see a lot of reason to buy a MSW right now. That being said, I think some devices like a cell phone charger or voltage adapter on a TV probably won’t care since they just step down the voltage and convert AC to DC.