You could use check valves, but in the same regard check valves can fail. The idea is IME more to have enough volume in the sump to hold the water that would need to come down to it in a power outage. If you are using a RR tank with a durso not much volume from the tank will go back to the sump. Once the syphon breaks that is it, and being in the basement would allow a larger sump as well. The distance the water is being pumped does not have to be that great either. Assuming the tank is directly above the basement sump, and you put the sump on a table, the height the pump would have to pump would be only 12'-13'. I am not sure the size display you are considering. In my tank I used the method recommended to me by Matt, I had an external overflow. I had 3 returns, with ball valves. I used the ball valves to have two just a few inchs under water and the other so just a little water trickled down it. This was no air was trapped and the overflow was silent. On top of that I drilled the return lines just under where they went under water in the tank so in a power outage, the syphon broke and not much extra volume was needed in my sump. Hope this makes sense to you.
For my 160 I was using a PanWorld 200PS, that ran the return split in two, a dual BRS reactor, a chiller, a deltec carbon reactor for bio-pellets, and although I didn't use a basement sump it had plenty of head pressure to have done this with ease if I wanted to. It did use 290 watts though.
My old smaller tank used a Eheim 1262 for the return alone, which runs a 80 watts. I also used several maxi jet 1200's for my reactors and such, at 20 watts a piece. I still used only 140 watts total going this route so considerably less energy use but for my larger tank the external pump worked well for me. The panworld was fan cooled and I didn't notice it adding much heat to the water, I can't say whether it added more then a eheim and maxis that were all submersed did.
I know my friend that has a basement sump makes me jealous. He can work standing up, drain his sump easily if he wants to clean the detritus from it. Also since he has a utility sink right next to it he can drain for water changes right to the sink. He also has the luxury of spacing his equipment out over a good work space. So his sump, fuge, chillers (2 for redundancy), reactors, etc are all out of sight and easy to work on.
This also allows him to use what ever height of skimmer he wants and isn't limited by the height on his cabinet. IMO if you can do a basement sump, it is well worth it.
