Im going to upgrade the breaker so its 20amp instead of 15. How should I do the surge protectors - split my 2 psus to 2 surge protectors? How do surge protectors limit the amount of power youre able to receive?
DO NOT DO THIS! NO NO NO!
Your wiring can probably only support 15A. If you upgrade the breaker to 20A it will likely cause the wires to overheat and burn your house down.
Hire an electrician and put in 30A 240V in your garage then use PDUs to distribute the power. You're asking for trouble by using residential lines.