There are 6 uniforms that you'll need to upgrade:
3E Urban Tracker
3E Black Arrow
VR Mozdok Telecom
Uniforms run for 200 a piece. (One is given for free)
5 Uniforms x 200 Points = 1,000 Points.
Each suit has 9 upgrades, running for 100 a piece.
6 uniforms x 9 upgrades x 100 Points = 5,400 Points
You will need a total of 6,400 Points to purchase everything available.
You DO NOT need to upgrade the "VR ZVEZDA" uniform (given through UPlay) to unlock this achievement!
To access the menu where everything is shown, enter deniable ops, then go to the box located in the top right. Under that, click "uniform". You will be brought to a screen full of uniforms, click them to display the upgrades.
Note: After purchasing the uniforms and gaining the achievement, you may quit out to the dashboard and save your money, and spend it towards other achievements.