MC34063A: Boost Converter Capabilities for 800mA output current

Hello,

I would like to know if the MC34063A or the MC33063A can be used for the following step-up/boost converter applications?

Input Voltage Range 5-12V

Output Voltage: 14 or 15V

Output Current: 800mA

Do we need to use an external NPN Transistor in like Figure 5 to handle the output current?

If yes, how should we go about selecting the external NPN transistor switch?

What are the expected efficiencies for this configuration?

Thanks,

Deniel