Overflow and return line

[Aquariumist]

I have a sump/refugium,and until now I didn't know that my tank had a tempered glass bottom. I need to have an overflow box for around 600 GPH. I also need to find the proper setup for the return line, how an I supposed rig it to keep from falling out of my tank. for the return line i am planning on a rio 2100 powerhead and appropriately sized return line. my problem is if im supposed to rig pvc, or some sort of pipe to the line from there? any input would be great.