If you have more than 1 servo-arm do you get that many extra attacks per round as your reaction? So 2 servo-arms get 2 attacks as your reaction or standard action?

You only ever get 1 attack action in a given round. If you have 2 servo arms you get to do neat stuff such as lift two tanks at once, or push apart giant blast doors. If one gets damaged, you can use the other one.

But attack with both in a single round? Maybe with some two-weapon fighting talents, but that would be up to your GM. One attack action per round.

If you have two reactions you might be able to spend it to make an attack with the other servo arm.