I assume that you are going to put both tanks at same level so they will operate at the same level. If that is not the case, come back for more info on how to manage it.
I don't like the inverted U because it is too easy to get a bubble in it. You can do it in other ways to avoid that problem.
I like to connect the tanks in series to avoid stagnation. Run the pipe from the source into the top of the first tank. Then pipe from the bottom of the first to the top of the second. Then pipe from the bottom of the second to your second pump or other distribution point. In this setup it is necessary to have the float control in the second tank, and the pipe from the first to second tank should be the full 2" pipe that is the usual outlet. No point of the pipe from first tank to second should be higher than the inlet to the second tank.
The other way is to connect the two tanks at the bottom outlets with the outlet to your system from a tee off the pipe between the two tanks. With that setup you can use the float switch on either tank.
I usually put the switch in the tank that is slightly higher, but set so it doesn't allow the lower tank to overflow. That gives you a little more clearance to install the switch.
If you are pumping from the tanks, you should have a float switch to detect "low water in the tank" condition to shut off the pump to prevent it from running dry and destroying the pump.