You could use a Y joint to split the output (parallel), but u need a stong pump to support both eqpt, which in return consume more elec (more heat).
I used to connect in series for my Q-tank, but usually this setup will not be strong enough to support the skimmer.
What eqpt are you using?
In the worst case scenario, if your tank has matured with lots of life rocks / sandbed, I would take the skimmer with high flow rate to ensure sufficient circulation..
As for corals, i recommend you to do some homework about the chemistry requirements.