So the trick to this approach is to let flows be independent of each other. Let the displaytank drain into the small sump at the same rate the return pump is feeding it back into the display. This is easy, it's just like a normal sump set up. The trick is sending water to the remote sump via a pump and letting it flow back naturally (basically another drain system just like of the display. If you can have the remote sump raised above the small sump under the tank and just use another herbie drain at the remote sump, you're golden. Think of the little sump under the display as a common sump for two displays. That's basically what you'd be doing. Just make sure the little sump can handle the extra volume of water from the two sets of pipes for when the power shuts off (so you don't flood that nice new house of yours).

If you have to pump the water to the remote sump, then pump it back then you are looking at having to match flows and the endeavor will probably be too complicated.

now your seeing i was right eh and we should have put the tank up to the window as per the origional plan , but you didnt want to give up the 2ft of floor space and now were in a worse situation.....i knew putting that tank against the wall was a bad idea and i said it from day one.....cpnsidering its an in wall tank

Ya, I was in a rush when I was typing earlier and didn't word it correctly. What you said is exactly what I was referring to (avoiding using 2 pump). Like I said in my post after, treat the little sump like a common sump between two displays with proper drain systems.