You could use an ez-coil or tap-sert to repair then use the oem plug. The hardest part for me is keeping the tap at a 90 degree angle. On my ATV differential, I didn't get it 90 deg and I just use some rtv on the plug/washer to make sure it seals. I suppose you could use a plug like some autos use which have a built in rubber sealing surface, or use a rubber coated washer made for oil drain plugs.
Either way, I've heard use plenty of grease on threads of tap or on threads of new oversized plug and I'd thread it in a little, then back out to clean the tap/plug, then regrease and thread it in some more, etc.