Wiring Power windows and seats questions

[chewychevy67]

OK. I'm going to share with you how I wired my power window/vent windows and seats. Am I OK how I dod this and the gauge wires I used. Also should I use a 30 amp breaker. I wired this like a 64 impala would have been from stock. I started with a 8 awg wire starting from the starter solenoid. 10 inches down that wire I ran a 30 amp breaker on the firewall. From there it runs across the firewall and down by the fuse box and into the cab (aprox 4 feet).Inside the cab it runs to this power block. (13 inches) All 8awg wire to here. From here I can plug my power seat and window runs. So I'm going to run 8awg from here to the seats that both are powered.aprox 4 feet of 8awg ). Power will be split under the seat with 12awg running to each seat switch and from there to the motor. These are all 60s gm switches. Now on the power window side I have power windows and power vent windows. 4 motors. From there it is 8awg to the harness (6 inches)where it splices into 12awg for the vents and regular windows (5.5 feet of 12awg from door switch to door switch). From there it goes to the factory 60s switches and to the motors. Should I be running 10awg in the window harness or will 12 be ok? I have a 40 and and 30amp breaker. I am assuming the 30 amp would be best? I am contemplating puting a 60s relay in the windows so they aren't powered all the time but the harness I got from the impala had power to windows all the time.