I bought a 28 inch light bar and wiring harness from Amazon.com. Total cost for the 2 items was around $60. A 30 inch bar would be better, I had to drill holes in the roof to mount mine. With a 30 inch you should be able to use the front bolts that hold the roof.
I ran the wiring harness from the battery through the plastic running board to a rocker switch in the panel, then wire tied the wire up the roll cage to the light bar.