A Vortex StrikeFire red dot would be a great optic for this rifle. It's cheap and it works.
If you wanted some magnification the little Burris 2-7X35 FFII Tactical would be a nice choice. At around $225 It's also affordable and has a "cool" factor to it.
I don't know why but I want one of those rifles. Everytime I see one Teenage Mutant Ninja Turtles theme music play's in my head!
Terry