Pretty much how I did mine. Stock ecu location.
I drilled a new hole down low on pass side for o2, maf, and few other wires(not finished still).

Then ran the rest behind the dash and to the drivers side.
The main engine harness I drilled a new hole for to the left of the heater core and out of sight behind the engine and ran the wires that way. You can't see them but its the general area where they come out
Then the rest I ran out behind the drivers side inner fenders and to the front of the core support and throught it.