I am using the eshopps pf800 on my 90.
All About Sumps - Page 3
It is a U-tube design.
I would also suggest increasing your sump capacity. I am using a 45 gal long tank for my sump. I have silconed in two plates of glass to make three sections. The last section for the return pump is a small section that only holds about 4 gals of water. That way, if for some reason the overflow box breaks siphon and water stops running from the tank to the sump, the only water that the return pump will be able to pump into the tank, is that 4 gallons. The overflow box is adjustable and it will determine your tank water level. If it is set low enough, that 4 gallons will not overflow your tank.
Now on your return nozzle...If the return pump stops running and if the return nozzle is set below the water line in the tank, however much water there is above it, that water will empty by reverse siphon into your sump. So what I do is set the return nozzle so that is is just breaking the surface. That also helps with surface aggitation. That way when the return pump is turned off, the return nozzle immediately sucks air and breaks the siphon and water will not run back down to the sump and overflow it.
You will get some water draining into the sump from the overflow yet, but if you set your baffles up in the sump so that the sump is only half or less than half full, you should have plenty of room for the sump to hold that water. That is why I suggest going with at larger sump. You will need room for enough water to run the skimmer and that extra room for the water from the tank if the return pump stops running.
Maybe I can do a video for you if you feel you need it.
Anyway, any more questions, dont hesitate to ask.