Thanks guys for some great suggestions. I appreciate them all.
I might keep the Type 87 AW turret as is. I like the sleek look of it and adding more stuff to it will make it look a bit too bulky. The twin Stingers look cool but only if I can find a set real cheap like what's on the Italeri Stinger Hummer. For now, I will probably only change the original single barrel 35mm Oerlikon's to the 20mm M61 Vulcans. The M61 Vulcans will give it that mean look, I hope!