I too am backing Railings as i got on it in the Caulfield Cup and am following it through.
The firm track is also bound to suit a horse like Leica Falcon also.
I currently have a key boxed trifecta on which includes:
To run 1st,2nd or 3rd
Makybe Diva, Railings, Eye Popper, Leica Falcon and Portland Singa
To run 2nd or 3rd
Vinnie Roe and Demerger
To run 3rd
Xcellent, Umbula and Strasborg
This cost $120 for a half unit(50 cents) and it give you 240 possible combinations for the trifecta.
I have thrown in 2 roughies for third in Umbula and Strasborg. Generally one pops up and these 2 horses are stayers who should be running out the trip.
Fingers crossed