Just wondering.

All of the LEDs on one string will be a "spot light", no control.
I would think you would want to be able to control at least "banks". You could then have dimming, blinking or what ever... For an idea...
http://www.picbasic.co.uk/forum/showthread.php?t=10200

As for the current. The LEDs will last much longer at 0.03 or even a bit lower. Running at the max will shorten the life a lot.

100 LEds at 0.03 is only 3 amps. A 10 amp transformer would take care of 300 LEDs. With some cushion