You're going to paint the truck and then work on it, and risk messin up the new paint? Not my truck, but if it were mine, I'd throw the air shocks in it. Whether they are flat, or pumped up from your air compressor at home. It's almost impossible not to touch the car when putting new suspension in.
On a side note, I'm really glad you picked a color besides blue. I think it'll look sick as hell. I'm also glad the jambs are getting painted too. Any chance that the engine bay will get painted as well? Either way, it's going to look hot. Way to come up on the accident lol.