[FotoPlasma]

As far as I know, you're supposed to power any custom circuitry with a single self-resetting 20Amp breaker, which supplies +12VDC. With that, you can use a voltage regulator (page 467 of the Digikey catalog) to regulate the +12VDC down to +5VDC, and supply +5VDC to whatever components need it, including the current sensing LEMs you're talking about.

Otherwise, you could just solder multiple connectors / wires to pin 1 on the analog input port, or to gang them, as you say, which would supply +5VDC to all connected components (if they're in parallel), but would be limited by the amount of current pin 1 can put out.

...

After checking out the RC manual, I see that pin 1 of the analog input port is fused by F3 on the RC. F3 is a 1.25Amp slow-blow fuse, and should be quite capable of supplying enough power for your needs (I tend to doubt that what you're thinking of doing would draw more than 1.25Amps), so perhaps ganging them all off of one pin is the best bet.