Can i put a larger U-Tube one a Eshopps pf300 overflow

You don't need to "match" them. An overflow only pulls as much water OUT of your tank as the return pump puts IN. An overflow has a maximum amount that it can pull out; as long as the flow from the return pump is lower than that, it doesn't matter. Even if the PUMP is bigger, you can restrict the flow rate with a ball valve on the return line, and tone it down until the overflow can handle it; tons of people do this. Just DON'T put a ball valve on the drain line from the overflow.

See, it works by you having a given maximum level of water in the dt. As water gets pumped into the tank, the water rises above this level, and the overflow takes some out to keep it at that max level. Simple, right?

I guess I was wrong, and used the DT volume instead of the sump volume for flow. At 10g, you need 100 gallons of flow, which is likely around what you're getting with your current pump.