I just read in The Farnam Method of Defensive Shotgun and Rifle Shooting that it is good to have 300 rounds loaded in magazines. I'm thinking that five or six magazines and the rest in stripper clips would work just as well. Besides, stripper clips are lighter. If SHTF I don't want to run out in a critical moment.
On which weapon to buy, I thought about that myself. I have a Mini-14. Nuff said. :-))
Don't pick a fight with an old man. If he is too old to fight, he will just kill you.