Do whatever you want, dude!
Personally, I would chose reverse glow, because the whole face lighting up would annoy me after a while.
However, the stock gauge lighting suck, so indiglos are a good solution. Other solution is to put some bright LEDs back there...
Soon, my 1W LED project will unfold... they're so damn bright in my early tests I've done that there was perfectly even lighting throughout the guage cluster!
