Must-haves would be types, not models, unless one is afflicted with gun lust (which is a malady I completely understand.) What model depends on preference and affordability.
Necessities
1) .22 rf rifle
2) 12 ga. - Pump is preferable, but dbl works.
3) defensive handgun
4) CF rifle (anything from a M-N on up)
If you can afford it
1) mil clone .223 autoloader
2) mil clone .30 - auto preferred, bolt better than nothing
3) concealed carry handgun
4) scoped CF rifle - .30 or better
Ammo availabiity
Good: If Walmart has it - .22rf, 38 Spl, 9X19mm, .45 ACP, 12 Ga, .223/5.56, .308/7.62X51, .30-06, .30-30.
Not so good: limited availability - .22 Savage High power, 8X56 Hungarian, 14 Ga, 7X61 S&H, etc. May be ballistically dandy, but without ammo an elegant club.