What is the dynamic head capacity of this pump?
You have selected the 230v model,  I have the 120V model.  The only standing water will be the 8' vertical to the ceiling and then a slight loop to the horizonal section.  The horizonal should still have a small slope toward the end where the water is discharged.
I cannot tell if your specific model has the check valve in the outlet.  None is described in the link to the pump description.  You will need the check valve.  At 10' vertical rise, it will pump 48gph, so 8' should not be an issue.