Hi BenK.
Using the standard aerial mounts can be tricky at times because of the spacing and the different mounting options between light bars. The 30" that I posted up above should work because the mounting feet are infinitely adjustable. If you wanted something smaller then you could also make the 20" work. Both of these use a 5w CREE LED.
If you were after more light output then I would suggest our LED lightbars that use a 10w CREE LED http://www.ledlightco.com.au/led-lig...tt-single-row/
The feet mount on the end of the lightbar and may require a custom mounting plate between the two aerial mounts.
Don't pay attention to the pricing on the website as NP members get a great discount and free freight.
If you have any other questions let me know.
Best regards,
Paul