TLC5940 and interrupts

Hi.

I have a Duemilanove hooked up to a TLC5940 chip connected as the playground tutorial and it's all working fine.

The TLC5940 library uses pin 3 to trigger GSCLK (via Timer2/ OC2B) My dilemna is that I'd also like to use both the interrupts (on pins 2+3). So I'm wondering whether...

a) I can change the GSCLK pin? I've had a look in the library folder and in ATMega_xx8.h there is a line "#define GSCLK_PIN PD3". Can that line be changed for another pin?

b)I can add more interrupts somehow? Some kind of external interrupt chip?

c) I should buy a Mega board with more interrupts.

Any thought/comments would be most appreciated. Thanks in advance. Colin