LOL poor Canuck, he will be back, I would have to agree, Talapia though good for people are not so good for salty preds, go with what you have, though there other options like other salt fish... but for the most part they tend to be rather pricey.
I would say that their current diet is good, you say salt bait fish... live I assume due to quarentine? What speicies? Anchovies? Silversides? As both of these (dead or alive, but none from the can they have to be freash haha) would be acceptable foods, fed hole being best as they have better nutrition due to organs and the like, if dead just get some tongs and wave the food-fish around infront of the pred and that "should" stimulate their feeding instincts.
Though I don't have much experience with preds as they sadly don't play nice in reefs
the canuck would be better to help you here, and you can always ask him when hes back (though I think hes using his GFs account at the moment so he may say something). But for now I'd say their diet is perfect (though sounds bit costly).
Have you tryed Fiddler crabs? dont know if they cost more or less then blues... heres a link to some good live invert for food site (haven't used them but Mr.Reef says they are good).
http://www.aquaculturestore.com/swinverts.html