DA,
Just to be a 'Devil's Advocate' - Just because a lot of other low cost airlines use 737s doesn't mean that that is the only aircraft type that would work. Whilst I know the shortcomings of the 146, the fact is that we were kicking ass on the PMO,FCO and CTA routes. Our load factors were incredibly high, and we were making moola. I am proposing that to kick off a new low cost airline, you would be better to stick with the current crews and with the 146 because until you reestablish the load factors, it will cost less to run 146s instead of 737s.
I Did not know that the 146s had been dropped from the BWA AOC, I didn't know that that was the case, for eg, I know of an airline that had 737s got rid of them for 146s yet still had the 737s on their AOC, years after they had dropped the 737s.