Like Namikaze said, it sounds like stuff to be discussed with a GM.
That said, as far Warhawks go, they're revolvers. You can't really do extended magazines with that, speed-reloaders and laser sights already exist and a smartgun system doesn't work with laser sights (the laser sight is redundant).
As far as the armor goes, it's a lined coat (or armored jacket) and a helmet; you can't stack form-fitting body armor like that.