Will you be carrying IWB or OWB? You mean big tall, big wide, or big both? If big tall, that'll help. Big wide makes the grips stick out some, depending on your build (barrel chest vs muffin top). I like the in the waist holsters myself, don't even own an OWB holster that didn't come with a gun (i.e., XD).
I had a P90, about the same size, and that sucker would be tough for anyone to conceal! Come fall, a vest will do you proud. For now, you'd just about have to have an untucked shirt to make it work. If you get one o' them Magnum PI hawaiian flowerdy shirts, with the loud colors, nobody will ever notice you printing....