That Ranger's owner put a lot of time and money into his truck in order to get it that low. Getting the rear end to sit low on a Ranger isn't too expensive, since its just a matter of flipping the axle, flipping the shackles, and notching the frame so the axle wont touch. Getting lower than that might require lowered leaf springs or airbags and a linked suspension setup. You'll also run into clearance issues with the bed and various suspension parts.
The front end is where it gets expensive. You can't go lower than 2 inches without aftermarket drop beams, otherwise you'll never get the alignment into spec. It might not seem like a big deal, but the truck won't steer correctly, it won't ride good, and it will wear the front tires out much faster than if the alignment was correct. You could chop the springs to get it really low, but its going to destroy the shocks and ruin the alignment. No way to fix that without replacing the beams.
It's just the nature of the front suspension design of our trucks. They won't drop without a bunch of money throw into them. Its pricy either way.... doing it right and spending the cash on aftermarket parts, or doing it cheap and spending money on replacement parts that are destroyed from driving it like that.
If i was you, i would get some drop springs for the front or cut a coil out of them, and flip the rear shackles. Thats good for 2 inches in the front and 2 in the rear. Put some bigger wheels on it and upgrade the shocks if they're worn out. Its a start, and it will look cool till you can put more into it.