Okay, I've just spent another hour going through the PP's and looking at about every angle I can think of, and Big Brown still is the horse who floats to the top. You might leave him off of some tickets just in case he trips or the huge crowd roar freaks him out when he breaks out of that 20 post, but that's flukey stuff no one can really anticipate. It is a horse race!
I like Colonel John but it's also true he'll probably be the second favorite, and though he's worked well on the dirt track at Churchill and had a great bullet work, it's true he's never actually run in a real race on dirt. So you could add in some other "seconds." One reliable horse is Court Vision, who has always hit the board, and has actually won on the track at Churchill Downs. Mott adds blinkers, and Garrett "Go-Go" Gomez is the jockey. Pyro is another possibility if you toss out the Blue Grass debacle, which could have very well been due to his not liking the synthetic track. Before that race, he had started to improve off his layoff, and Steve Asmussen is the trainer of the remarkable Curlin.
If she gets a good break and manages to get over to the rail to save ground (and, let's hope, box out Denis of Cork and Calvin Borel, Eight Belles could get up for third. As a filly, she also gets five-pound weight break. Her jockey's never ridden in the Derby, though, so he may make some miscalculations. Another possible longer shot is Visionaire. That's Barbaro's trainer and he's in same Derby slot, too--the 8. He's not the fastest horse, though, but I'll give him this: he's got a lot of heart. He's also always hits the board except in the Blue Grass, so maybe he didn't like the synthetic track, either. Despite that, he was making a move and gaining quickly on the leaders. Gayego is another good choice who has always hit the board and who has won on both dirt and polytrack. Mike Smith's aboard, and he rode Giacomo to victory in the Derby. I don't like the 19 gate spot, though. It's a disadvantage, but it's possible he could get up to third.
So, this gives us 20/9,10,4/5,8,19,9,10,4 as a much cheaper trifecta than the one suggested below. You can then throw in a few other horses to finish out a superfecta. Possibilities are Monba, Smooth Air, Tale of Ekati, Z Fortune, or Bob Black Jack (who will probably set the pace or at least be close up front but I think he'll tire...yet he could hang on for a piece).
If you're doing a Pick 3 or 4, for the Derby leg, I'll probably go with 20,10,9,4.
Again, good luck!