Thanks for the replies. I realize now I didn't include many details.
The battery will be in the stock location, the computer will be in the driver's side battery location. I'm not using the Subaru ECU, I'm going with Megasquirt. From what I've read so far, the computer needs power when the key is turned on and when the starter is going. So I have to run the wires to the front. I completly forgot about audio signals too.
So, I have CHT, Water Temp, Oil Temp, Tach, Oil Press. I can run these singal wires together in their own loom, I just have to sheild them away from the power wires?
I'm needing some sheilding anyway. Where can I get some for this too?