I think this is the only time I'd ever suggest using the Tier Tactical 2 pack. It has an ammo system, far better than the BF3 pack, and has many different styled weapons, so it is fairly easy to "upgrade".
Trust me, I don't like the T+T2 pack, but for what you're doing...you'll need it.
The T+T2 pack is nice, but it's only got two upgrades, no iron sights, no reloading animations iirc, and the weapons are just generic block style guns.
Also limited ammo (reloads) is somewhat annoying, because let's say you run out of ammo, are you really supposed to just Self Delete?