The little old mods which add M4A1 and RO635 as Outfits
Models by empty:

• RO635: https://emptyskk.gumroad.com/l/RO635?layout=profile
• M4A1: https://emptyskk.gumroad.com/l/m4a1?layout=profile

Issues:

• Arms (especially hands and fingers) looks off

Spoiler!

If you have the old GFL Characters Pack and AR-15 Outfit, you can make the Anti-Rain Team to rob the bank :v