I think the new blueline HD pumps are terrific. Very similar to the japanese iwakis. If you're moving lots of water through the tank without the return, you can have a smaller return pump; maybe 700gph or so. This will provide you with enough flow through the sump for a skimmer, heater, refugium, etc, and keep your overflow quiet, help with heat and electric bill. The GRI pumps have a great reputation, but I think they're a bit noisier than the iwakis or blueline HD. Not sure about that. One thing to remember is that you don't need a pressure rated pump for a return; this can help with flow, heat, and power consumption. Maybe think about the iwaki 30rxt or blueline HD 30-X. There's probably an equivilent GRI, but I think they're more known for the quality of their pressure pumps.
Again, I'm not sure about that, but somewhere I remember reading about it.