Advice on return pump

Hey guys, new here and am trying to spec out my first reef tank build. I decided on the Innovative Marine nuvo fusion 20 gallon tank, and was wanted to upgrade the return pump. I was looking at the tunze silence 1073.020 it has about 600gph and I was wondering if this would be too much flow for mixed tank comprised of mostly LPS, (1-2 pieces of LPS) and some softies. Also keep in I would NOT be using any other powerhead on this tank if using this return pump. IF this would be too much flow would it be better to keep the stock return pump and go for something like the tunze nanostream 6020?

Thanks