I am sure your boxers will be fine. I would take the day off work after the neuter, rather than the same day. Then you will be home and can try and keep them calm.
They will be up and wanting to run around in no time.
Tara, IWS 5/17/02 -
Dante, Male Brindle 3/18/10 - Adopt 5/13/13
At the Rainbow Bridge, Markus and Terramoto