Hi, I'm having a very hard time finding good gear for big guys. I'm 6'2 340lbs. My chest is about 57", my waist is 48", and my arms are about 21". All the good name brand outer shells only seem to come in xxl. I think I would need at least a xxxl, or maybe even a xxxxl. Ideally, I would like to get a shell that would fit over my xxxl northface nuptse. The northface jacket just fits me, I was shocked to find a puffy that fits. Any help would be appreciated. Thanks!