Should be fine.
Dont forget your headloss though from the pump. Maybe you should of gotten a 600GPH pump as well because it going up however far, It'll loose "GPH
But it'll work.
To test if you have a power outage or siphon break..
Pull the plug on the tank.. Watch the water go into the sump and see where it stops by itself.. (where the overflow box stops siphoning).
If you see it and its going to overflow the sump, break the siphon.. and obviously your going to have to have your sump less full unless you want a flood in a power outage.
Now to test your siphon breaking.. Well you dont really need to test it.
But a float switch is a good idea for a pump. Connect it all up and if your siphon breaks the float switch goes off and turns the pump off stopping the pump from pumping all the water into the DT causing it to flood.
Also, Be aware that the return pump that goes into the DT will siphon to the sump as well when the power goes out or if you run that float switch. So make sure your return line into the DT is as short as possible to the waters surface in the DT.
Hope ive made sense. Lol.