Yeah, too much to cover with a normal brush. I used a light coat of Citadel white primer, very light. With airbrushing I don't have too much trouble with white or black, airbrushing gives you plenty of coverage, especially since layers dry quickly and you can keep going over it until you get what you want.
(On a side note, you can get good bright colors over black by using the Citadel Foundation colors and then building up layers of brighter color on top of that.)
For this project I'm using the same colors as my Fire Hawk army (similar orange can be found my some Mandrakes I did a while back): the base coat is a combination I mixed of Tamiya Orange and Hull Red, with a little bit of brown and red ink thrown in, which makes for a nice burnt orange color. The dark parts are straight Hull Red and the highlights are straight Orange. The base color is almost exactly Macharian Orange, from the Foundation range and I use that for touch-ups. I think the key is the Hull Red, which is a really dark red-brown. It makes the orange brighter, but isn't as dark as brown or black that would be too contrasty.
Now I just need to go over all the metallics and hit a few places with black. I finished the cockpit this weekend, now it is all exterior work.
The nice thing about orange is that both green and blue make really strong contrasts-- I did all the controls in the cockpit in green and it came out pretty nice.