Leasing is the most expensive way to buy a car. You might get a smaller payment, but at the end of the lease, you owe a lump sum for the car. Most people will trade them in instead of buying it, so in essence leasing is like renting. You never really own the car, unless you can pay off the balance at the end.
Buying used makes more sense than buying new, because of the depreciation factor. I've heard that the price of SUVs is really coming down now. Are you sure you want to put the gas in an SUV? My husband has a Toyota 4Runner and it costs him $75 to fill it up. My car is half of that. I drive a really tiny car though--Scion xD-34 mpg.
Good luck