MOR
The Saab 2000 has been all but ruled out due to it's lack of efficiency - how the 328 compares to that is niether here nor there.
The reason CT7 probibly didn't mention the Q400 is the 70 seats inside - perhaps a good option for MC when they want to replace the ATR 72s, but not in the ball park for RLK.
As for jets - not really a concideration, any operational benifits are far outweighed by capital outlay/leasing cost.
I see not one of your sugestions for a 30-50 seat aircraft actually fits in that size range.