I'd say a Mag 18 or 24, Quiet One 6000 or 9000, or maybe OceanRunner 6500. Max flow is going to depend on how you do your plumbing. I think the Mag 18 is the best bet. Have used them for years with no problems. I have a Quiet One 9000 and the first time I tried to clean it, I broke the ceramic shaft, making it useless. It made some loud noises at startup sometimes too. The mag 18 seems a bit more effecient than the 24, have both of these also. The 24 would need to be reduced with a ball valve, unless you plan on having it do more than just return water to the tank. When I was using the 24 on my 120 I had a heat issue with it. The 18 is what I run now and no probs. Hope this is helpful
Matt