Buy PACA body armor and a 6б47 helmet from Ragman, RFB with M61 or KRISS Vector with AP 6.3 ammo, and go on Factory to camp in the offices where the safe is located.

As for the guns, you get the AK-74N craft it at the Workbench level 1, find it on Reserve or on dead scavs. 

M4A1 you get for the quest , it can also be found on killed raiders.

Makarov PM pistols can be found on dead scavs or in the ammo crates.

If you are trying to make the most significant profit, then you can remove all modules from the АК and М4 except the critical ones, so that the weapon does not turn “red” in the inventory. Prapor will accept such a gun, and you can sell the removed modifications to save an extra penny.

Craft AK-74N:

Hideout module	Components		Produced item(s)
Workbench 1 level	Components	WParts 18 000 ₽ For 1 item at the flea market 6P20 Sb.6 9 999 ₽ For 1 item at the flea market 6P20 Sb.5 9 999 ₽ For 1 item at the flea market Pliers 12 000 ₽ For 1 item at the flea market Reusable crafting item Scdr. 3 000 ₽ For 1 item at the flea market Reusable crafting item 35 888 ₽		Produced item(s)	AK-74N 1 h 21 min