rfid and stepper

[system]

I am wanting to have an rfid reader ( I'm receiving a parallax) to recognise an rfid and turn on a stepper motor for 12 seconds. the stepper motor is bipolar and runs at 27v and 16[ch937]. I am also going to use this motor sheild
http://www.oomlout.co.uk/motor-shield-for-arduino-kit-p-207.html?zenid=486faeab903884acf8bfb8e5c39296bc
is this possible and if so will I need 2 power supplies?

thanks in advance much appreciated

[Grumpy_Mike]

The data sheet for that controller says:-

L293D chipset provides 0.6A per bridge

Ohms law says:-
27V into 16R gives 1.68 Amps.

I say:-
No.