Just tested (very roughly) without a transistor and it seems that the contrast acts just like a normal LED.
Ripple isnt a problem. A 0.1uf capacitor should just smooth things out a bit though.
Ok last questions:
Is a resistor required on the LCD's backlight? Sparkfun doesnt use one. I'd imagine it would be fine.
And is a resistor required on the transistor's base? I wouldnt think so.
I will be rather happy if I can ditch two resistors. 
I'll then be able to order.
Current parts list (assuming I can ditch two resistors):
2x 0.1uf 0805 capacitor
2x BC817 SMD NPN transistor (0.8A max)
1x 10k 0805 resistor
1x ATmega8 QTFP