The normal Equipment menu of the terrorists does not have the shield option. But for some reason, the "buyequip" does.
Make sure that a T calls the Equipment menu by pressing the "buyequip" key that's normally bound to "O".
You can also use "shield" in console to buy a shield.
Kudos to Ronkkrop for finding the shield offset! ^^
Note: If you're running on AMD64 servers, be sure to uncomment the AMD64 define before compiling.