You can get it from here https://thinlinesanctuary.com/products/duty-belt-package
Unfortunately not, the 8.3 version is now outdated and unsupported but thought that it might be to keep around for people who want the 8.3 ver.
https://www.gta5-mods.com/weapons/colt-m4a1-m203
Yeee
For Vest
OffsetPosition = 0.1,0.24,0.00
Rotation = 180,125,-15.00
For non vest
OffsetPosition = -0.1,0.22,-0.02
Rotation = 165,165,0.0