Painting Steel Tray Options??

[mickkk]

I have my tray off my triton for a few reasons. Im installing a 120l polly tank, and a 58l water tank. Im also making new tray rails to help stiffen up the chassis (150mm C channel).

My tray is painted white, but its all chipped and seen better days. By the time I have finished it will need another paint. I was thinking about powder coating, but I don't want to have to get it sand blasted and don't really have the time as Im doing the Madigan's Line over Easter (hence the extra fuel and water tanks)

My question is what should I paint it with. I want to paint it black to match the rest of the things I have bolted on. Not too fussed on the finish, but want it hardy and be able to resist the pressure cleaner.
Might seem an odd question, but I remember seeing other builds and some one using something to paint the under side of their tray and I remember thinking I will do that if I have my tray off. But for the life of me I cant remember what it was (this may of been maccas tray build on his madaza)

I have an airless spray gun, which may not be ideal, but as I said not real fussed on finish.

Hopefully some one can point me in the right direction (other wise I will he heading to Bunning's for a bit of etch primer for the new steel work, and a box of black rust guard in spray cans) but Im sure the will be a batter option.

Cheers Mickey