How about these? 144 leds per metre, double the brightness if you need to make your strip less than 12".WS2812 use up to 60 mA per led. However, that maximum is only when displaying full brightness white. When yellow, the current will be only two thirds of that. Flashing patterns even less.
Are there any boards that are 12v? I feel like it'd be easier to keep the whole system 12 volts.