About the armor: I don't know if it's possible, but the best way would be to add different protos and force the game to read them instead of the old ones after the armor has been bought (save level 0 ofcourse, which would screw level-uping). As for the stats, contrary to popular & wrong belief, the "unarmored" NPCs like Marcus and goris have a DR more or less equal to power armor (both have 40% for normal weapons, for instance), and they are only a bit inferior due to lower DT (For normal damage, Goris has 6, Marcus and Brain bot has 5, Power Armor has 12), making them susceptible to burst weaponry. A decent addition to DT and slight tune-up for the DR (+10% perhaps?) would be imho the best for Marcus - Lets not forget his higher HP count, overdoing his armor bonus would make him way tougher than the guys in power armors, which is kinda ridiculous. As for dogmeat, contrary to the other "unarmored" NPCs he suffers from terrible DR/DT and to make him on pair with the others in terms of survivability, he would have to get an absurd bonus from his dog armor, which is pretty un-logical (a kevlar plate with better stats than Power Armor, yeah, ofc.). It can ofc provide a more mild bonus, but it will not make dogmeat much more useful, I fear, since his DR/DTs are rather pathetic, and raising them by a small amount will not help. Deathclaw armor would also be interesting (Goris doesn't have a lot of protos since he can't use weapons ).