Welp, I have a pretty good setup for FO3 but it lacks guns and armor
Do ya'll have some recommendations ?

Fallout 3 was never that great for weapon mods (probably because the combat sucked). You can find a lot of decent ones included in FWE and classic fallout weapons. EVE also includes a lot of awesome energy weapons and is a must for any playthrough. Armor really depends on what you are looking for tumbajamba, Gopher, ghouls0rules, daejones and hideouscircus are all good. I also did a few armor mods