I like the Hydor Koralia wave pumps, the new evos are nice. low power, with good flow. wave maker compatible. Plus they come with magnet suction cups, no falling off in your sand. Shop around you can find them at a decent price. I just got 4-1050gph for $140, that should be plenty of flow in a 70gal.
I tested both Koralia Evolution 1050 and Voyager 3 in my LFS, I like the Voyager better, more quite, always starts in same direction (so compatible with wave makers) vs Evolution make noise when it doesn't start right. I ended up picking up 4 Voyager 2, 3 is too much for my small 65G