I am looking to install the level 2 charger myself and I was wondering which cable to do I need for an outdoor application for a 40 AMP breaker. I know that Romex 8/3 Stranded CU SIMpull NM-B Wire works for the inside but I actually need a cable for outside and I think the only one I can find is the SOOW, 600V cable but I am not sure if it's right for the 40 AMP breaker.

Marine shore-power cord is generally rated for 220V because it's used across the pond and not just here in the US, and it's outdoor-jacketed and comes in a 50A variety. Try West Marine.