After the release of battlefield 1 I have began to wonder and try my best to make my game feel like WWI with rifles, trench knives, etc I would really like to know if you guys know of anything that contains WWI themed armors and apparel.

http://www.nexusmods.com/fallout4/mods/15469/?

http://www.nexusmods.com/fallout4/mods/17571/?

Well, there's these. You can make a Gewehr98 by modifying one of the base guns in the "Mauser Family" mod. And the second link shows three melee weapons used in the time period. Hope that helps.

I made a retexture of LordOfWar's "The Rebel" outfit in a WW1 theme.

Can check out some pics here, and there's a link on that page to the textures also.

Any chance anyone is working on a WWI/ WWII themed outfits for fallout 4? It's almost lore-friendly as Fallout is stuck in the mid 1950's era.

Yang1200 you can find some WW2 uniforms and outfits on nexus.
WW2 German Uniforms
WW2 Two-Tone US Army Uniform