http://palmer-pursuit.com/cart/air-s...age=2&sort=20a
You can buy a rig here and add an "in line" thatll be your seccond regulator.
Less then 300 bucks.
You can run it without the seccond regulator its just a preference of mine to have two.
In that case itll be less then 200.
If you want small you can get the ones that run off 12gr co2